User:Sandbh/sandbox

Observational

Observational criteria are properties or behaviors that can be directly measured, observed, or tested empirically, and which help distinguish between metals and nonmetals based on their physical appearance, chemical reactivity, or everyday behavior — such as conductivity, luster, density, or acid–base character.

Density and electronegativity

Density and electronegativity in the periodic table[a] H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po Rn Ra                                                                                                                                                 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Ac Th Pa U Np Pu Am Cm Bk Cf Es Electronegativity (EN): < 1.9 ≥ 1.9 (revised Pauling) Density (D):  < 7 g/cm3  D < 7 and EN ≥ 1.9 for all nonmetallic elements ≥ 7 g/cm3  D ≥ 7 or EN < 1.9 (or both) for all metals

Several authors^[11] have noted that nonmetals generally have low densities and high electronegativity. The accompanying table, using a threshold of 7 g/cm³ for density and 1.9 for electronegativity (revised Pauling), shows that all nonmetals have low density and high electronegativity. In contrast, all metals have either high density or low electronegativity (or both). Goldwhite and Spielman^[12] added that, “…lighter elements tend to be more electronegative than heavier ones.” The average electronegativity for the elements in the table with densities less than 7 g/cm³ (metals and nonmetals) is 1.97 compared to 1.66 for the metals having densities of more than 7 g/cm³.

Theoretical

Theoretical criteria are model-based or principle-driven concepts that seek to explain or predict metallic or nonmetallic behavior using underlying physical laws. They aim to describe why a substance behaves as it does, rather than merely what it does.

Reply to Ldm1954

@Ldm1954: Thank you for your reply. I respectfully disagree with the characterisation of my post as WP:SYNTH, WP:OR, or WP:CHERRY. I have cited page numbers directly, distinguished clearly between quoted material and commentary, and referred to reliable secondary sources in support of key points.

I want to emphasise that my aim is not to challenge the validity of solid-state physics or band theory — both of which I respect — but rather to question how Ashcroft & Mermin (A&M) is being used as a source in the Nonmetal article. Several of their statements are either internally inconsistent or overgeneralised, and in a general encyclopedic context, those issues warrant clarification.

For example, A&M refer to boron as an insulator on p. 60, and then as a semiconductor on p. 564, without explanation. While the Nonmetal article does not cite A&M’s broader claim that “metals are ductile and malleable” (p. 2), I mentioned this to highlight a pattern of overgeneralisation within A&M’s descriptions — particularly since they themselves assert that “even to understand nonmetals one must also understand metals.” That seems a fair point, and one which arguably ought to be reflected in the article, but which you previously removed: . These examples, taken together, highlight a combination of terminological ambiguity (in the case of boron) and factual overstatement (in the generalisation about metallic properties) that could confuse non-specialist readers — i.e., the Wikipedia target audience — if presented without qualification.

You mention that “it is completely legitimate to refer to diamond as both an insulator and a semiconductor.” I would suggest that this statement needs important context: pure diamond is a wide-bandgap insulator (∼5.5 eV) and does not conduct electricity at room temperature. It becomes a semiconductor only when doped, e.g. with boron or phosphorus. Since the Nonmetal article explicitly concerns chemical elements, it seems out of scope to refer to doped diamond, which is an intentionally modified (impure) form of elemental carbon containing trace amounts of other elements. While doped diamond can exhibit semiconducting behaviour, pure diamond — the undoped elemental form of carbon — remains an insulator, and it is this form that is relevant to the article.

In sum, my goal is not to necessarily diminish the importance of A&M, but to ensure that if their text is cited, it is presented with appropriate context and clarity for a general audience. If there are specific instances you believe I have misread or misrepresented, I would welcome your clarification.

Some further concerns (final)

5. On p. 2 of their book, Ashcroft and Mermin write:

Metals occupy a rather special position in the study of solids, sharing a variety of striking properties that other solids (such as quartz, sulfur, or common salt) lack. They are excellent conductors of heat and electricity, are ductile and malleable, and display a striking luster on freshly exposed surfaces.

The relevance of this passage to the Nonmetal article is that, as A&M write later on the same page, “even to understand nonmetals one must also understand metals.”

That said, I describe the passage as being stated flatly, since it is neither qualified as a generalisation nor presented as a being typical summation.

It is in fact demonstrably false: several metals — including beryllium, chromium, tungsten, manganese, osmium, bismuth, and plutonium — are brittle.

6. In the same passage quoted above, A&M also assert that metals display a striking lustre on freshly exposed surfaces. However, arsenic — a semimetal in the physics-based sense, and one which they classify (p. 726) as a nonmetal — displays precisely this kind of metallic lustre. This undermines the implied uniqueness of metallic lustre as a property exclusive to metals and highlights further ambiguity in A&M’s treatment.

7. On p. 563, A&M write:

The conductivity of a metal...declines with increasing temperature... The most striking feature of semiconductors is that, unlike metals, their electrical resistance declines with rising temperature.

This statement is false. Plutonium, widely recognised as a metal, exhibits increasing conductivity with temperature in the range −175 °C to +125 °C. See: Russell AM & Lee KL 2005, Structure–Property Relations in Nonferrous Metals, Wiley-Interscience, New Jersey, p. 466. This is not a trivial anomaly but a well-documented counterexample to their binary characterisation of metals versus semiconductors.

8a. I earlier noted (see item 2a above) that A&M referred to boron as an insulator (p. 60). On p. 564, they go on to write:

Semiconducting crystals come primarily from the covalent class of insulators. The simple semiconducting elements are from column IV of the periodic table, silicon and germanium being the two most important elemental semiconductors. Carbon, in the form of diamond, is more properly classified as an insulator, since its energy gap is of order 5.5 eV. Tin, in the allotropic form of grey tin, is semiconducting, with a very small energy gap... The other semiconducting elements, red phosphorus, boron, selenium, and tellurium, tend to have highly complex crystal structures, characterized, however, by covalent bonding.

In our Nonmetal article, boron is referred to as an insulator — which is only part of the story. Even A&M later describe boron as a semiconductor, and other sources consistently classify it as such.

8b. While the crystal structures of boron and red phosphorus are indeed highly complex, this is not the case for selenium and tellurium, which consist of relatively simple parallel covalent spiral chains. These chains are weakly bonded to one another via metallic interactions. There is thus no general tendency for semiconducting nonmetals to possess highly complex crystal structures, as A&M imply.

9. After asserting that diamond is “more properly classified as an insulator,” A&M then include it (p. 566) in a list of selected semiconductors. This again illustrates internal inconsistency in their treatment of nonmetallic semiconductors.

Conclusion

These contradictions render A&M’s descriptions not only inaccurate, but at times careless or overly idealised — especially surprising in a text that elsewhere emphasises physical rigour.

If A&M is to be cited in the Nonmetal article, we should do so with caution and avoid reproducing such contradictions without clarification or qualification.

Ideally, while age alone does not disqualify a source, the several shortcomings of A&M (1976) suggest the need for a more up-to-date and element-informed source — particularly for an encyclopaedic treatment intended for a general audience.

Some further concerns

5. On p. 2 of their book, Ashcroft and Mermin flatly state:

Metals occupy a rather special position in the study of solids, sharing a variety of striking properties that other solids (such as quartz, sulfur, or common salt) lack. They are excellent conductors of heat and electricity, are ductile and malleable, and display a striking luster on freshly exposed surfaces.

The relevance of this part of A&M to the Nonmetal article is that, as they write later on the same page, even to understand nonmetals one must also understand metals.

Now, I described the quoted passage about the striking properties of metals as being flatly stated, since it is neither qualified as a generalisation nor presented as a typical property with known exceptions.

Yet it is demonstrably false: several metals — including beryllium, chromium, tungsten, manganese, osmium, bismuth, and plutonium — are brittle.

6. In the same passage quoted above, A&M also assert that metals display a striking lustre on freshly exposed surfaces. However, arsenic — a semimetal in the physics-based sense, and one which they classify (p. 726) as a nonmetal — displays precisely this kind of metallic lustre.

7. At p. 563 A&M write:

The conductivity of a metal...declines with increasing temperature...The most striking feature of semiconductors is that, unlike metals, their electrical resistance declines with rising temperatue.

This statement is false. Plutonium, widely recognized as a metal, exhibits increasing conductivity with temperature in the range –175 °C to +125 °C. See: Russell AM & Lee KL 2005, Structure-Property Relations in Nonferrous Metals, Wiley-Interscience, New Jersey, p. 466

8. I earlier noted [item 2a, above] that A&M referred to boron as an insulator (p. 60). At p. 564 they go on to write:

Semiconducting crystals come primarily from the covalent class of insulators. The simple semiconducting elements are from column IV of the periodic table, silicon and germanium being the two most important elemental semiconductors. Carbon, in the form of diamond, is more properly classified as an insulator, since its energy gap is of order 5.5 eV. Tin, in the allotropic form of grey tin, is semiconducting, with a very small energy gap...The other semiconducting elements, red phosphorus, boron, selenium, and tellurium, tend to have highly complex crystal structures, characterized, however, by covalent bonding."

In the Nonmetal article we refer to boron as an insulator, which is telling only part of the story. Even A&M refer to B as a semiconductor.

While the crystal structures of boron and red P are highly complex, this is not the case for Se and Te which comprise parallel covalent spiral chains, with evidence of a weak metallic interaction between the neighbouring atoms of different chains. There is thus no tendency to have highly complex crystal structures as opposed to relatively straightforward chain structures.

9. Having earlier written above that, "diamond, is more properly classified as an insulator" A&M then include diamond in a list of selected semiconductors (p. 566).

Conclusion
These contradictions render A&M’s initial description not only inaccurate, but represent a striking example of careless or overly idealised writing — especially surprising in a text that elsewhere emphasises physical rigour.

If A&M is to be cited in the Nonmetal article, we should do so with caution, and avoid reproducing such contradictions without clarification or qualification.

Ideally, a more up-to-date and element-informed source would be used in its place.

I will go further and say that, while age does not automatically disqualify a source, there are presumbaly more recent sources that could be used in place of A&M (1976), given its shortcomings.

Concerns about classification of C, As, and Sb as metals

The final paragraph of the lead section currently reads:

"In contemporary research usage it is common to use a distinction between metal and not-a-metal based upon the electronic structure of the solids; the elements carbon, arsenic and antimony are then semimetals, a subclass of metals. The rest of the nonmetallic elements are insulators, some of which such as silicon and germanium can readily accommodate dopants that change the electrical conductivity leading to semiconducting behavior."

I feel that this framing is problematic in light of the article’s own definition of a nonmetal—at the start of the lead—as an element that "mostly lacks distinctive metallic properties." It goes on to refer to such properties as both physical and chemical. That is to say, the assessment of an element's status notionally involves a consideration of both its physical and chemical properties.

Over the years, in an effort to simplify this process, about two dozen different (usually singleton) properties have been suggested as signature criteria for distinguishing elements that are metals from elements that are nonmetals — including electronic band structure.

This particular property ostensibly leads to carbon (graphite), arsenic, and antimony being included among the metals (i.e., semimetals in the physics-based sense).

But this overlooks the fact that when the full suite of physical and chemical properties is considered, all three fall on the "not-a-metal" side of the line — on the basis that they lack a predominance of distinctive metallic properties in both physical and chemical terms.

While electronic band structure is arguably more fundamental in a physical sense than many other criteria (such as bulk coordination number or thermal conductivity), it is not inherently superior as a classificatory tool. Classification in this case depends not just on the depth of a property’s theoretical foundation, but on its relevance to the broader chemical and physical behavior of the chemical element in question.

Curiously, Ashcroft & Mermin (1976, p. 726) in Solid State Physics, count C as a nonmetal even though it has the electronic band structure of a semimetal.

As the article notes, there is no widely accepted precise definition of a nonmetal, and any list of nonmetals is open to debate and revision. Ditto, there is no widely accepted precise definition of a metal.

In a related manner, the Structure, quantum mechanics and band structure section represents a disproportionate emphasis on electronic band structure as a signature classification criterion, which can mislead readers about the broader chemical context of nonmetals.

To address this, electronic band structure should be presented as one of multiple criteria used to characterise the elements, with appropriate emphasis that chemical properties are equally important.

This balanced approach would provide readers with a more accurate and holistic understanding of the classification of the chemical elements.

Concerns about Ashcroft & Mermin's [A&M] Solid state physics (1976)

The title and publication details of this book are:

Solid state physics, Saunders College Publ., Fort Worth, Philadelphia

It is cited four times in the Structure, quantum mechanics, and band structure section of our Nonmetal article.

My observations follow.

1. A&M write at p. 2:

"Even to understand nonmetals one must also understand metals..."

A fair point, which presumably ought to be reflected in our article.

2a. A&M write at p. 60:

"Why Are Some Elements Nonmetals? A more acute inadequacy of our rule of thumb for determining the number of conduction electrons is posed by the existence of insulators. Why, for example, is boron an insulator while its vertical neighbor in the periodic table, aluminum, an excellent metal?"

Rather than as an insulator, boron is well known as a semiconductor. See: Berger LI 1997, Semiconductor Materials, CRC Press, Boca Raton, pp. 37–43.

Steudel (2020, p. 224), who is also cited in the same section of our article, similarly writes:

"Boron is a semiconductor in all of its modifications with bandgaps for α- and β-rhombohedral boron ranging from 1.6 to 2.0 eV."

2b. On a related note, our article goes on to say:

"Band structure definitions of metals and nonmetals are widely used in current research into materials, and apply both to single elements such as insulating boron[215]..."

In this case, citation [215], notes the semiconducting properties of boron about ten times, and not at all as an insulator.

3. In our article, A&M chapters 8 and 19 are cited in the following following passage:

"From this the concept of nonmetals as "not-a-metal" originates. The original approach to describe metals and nonmetals was a band-structure with delocalized electrons (i.e. spread out in space). A nonmetal has a gap in the energy levels of the electrons at the Fermi level.^{[206]: Chpt 8 & 19}  In contrast, a metal would have at least one partially occupied band at the Fermi level;^[206] in a semiconductor or insulator there are no delocalized states at the Fermi level, see for instance Ashcroft and Mermin.^[206] (A semimetal is similar to a metal, with a slightly more complex band structure.) These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott,^[207]: 257 and the equivalent definition at other temperatures is also commonly used as in textbooks such as Chemistry of the Non-Metals by Ralf Steudel^[208] and work on metal–insulator transitions.^[209][210]"

Here, the citation of Chpts 8 & 19 appears to be misplaced—neither chapter discusses nonmetals specifically. Chapter 8 discusses semiconductors and insulators. Chapter 19 (p. 377) says, "Ionic crystals, such as sodium chloride are compounds composed of a metallic and nonmetallic element."

4. A&M at p. 726 present a periodic table in which the "nonmetallic elements" are shaded as:

H; B; C; N, P, As; O, S, Po; F to At; He to Rn.

From their periodic table, the status of Si, Ge, Se, and Te is unclear. In real life these elements in their most stable forms in ambient conditions are well known as semiconductors, but so too are B, P, and I—elements A&M classify as nonmetallic.

Note that C is shaded by them as a nonmetal even though, in its most stable form of graphite, it is a semimetal in a physics-based sense and hence a metal in the physics-based sense.

Note further that while As and Sb are both semimetals in a physics-based sense and hence metals in the physics-based sense, As is classed by A&M as a nonmetal whereas on their periodic table the status of Sb is unclear. Elsewhere in their book they show Sb as a metal (pp. 5, 21, 38, 48, 364). The logic here is unclear.

Concluding observations
Given the concerns raised above, we may wish to consider the following improvements to our article:

• Clarify that A&M’s discussion of boron as an insulator (p. 60) is not consistent with its classification as a semiconductor in more recent and widely accepted sources, including Berger (1997) and Steudel (2020). Citation [215], currently supporting boron's status as an insulator, also needs revision.

• Re-express or qualify the reference to A&M Chapters 8 and 19 in citation [206], as these chapters do not directly address the classification of nonmetals and do not appear to support the statements made in the paragraph in question.

• Acknowledge the confusion in A&M’s classification of elements such as silicon, arsenic, and antimony, with the latter two variably treated in physics- and chemistry-based schemes. Their depiction of carbon, arsenic, and boron also merits comment, given the physical forms in which these elements commonly occur and their electronic properties in those forms.

Overall, while A&M may have been regarded as a landmark text in solid-state physics, some of its examples and classifications may not reflect contemporary chemical understanding or may require contextualization when used in a general encyclopedia article.

I welcome further thoughts on how best to proceed.

Concerns about Steudel's Chemistry of the Non-Metals (2020)

The title and publication details of this book are:

Chemistry of the Non-Metals: Syntheses - Structures - Bonding - Applications, De Gruyter, Berlin

Steudel is cited as [200] in the following passage of the Nonmetal article:

These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott,[199]: 257  and the equivalent definition at other temperatures is also commonly used as in textbooks such as Chemistry of the Non-Metals by Ralf Steudel[200] and work on metal–insulator transitions.[201][202]"

My observations follow.

1. Cite 200 is to p. 154, where Steudel writes:

"The strictest criterium to define nonmetals in contrast to metals is the electric conductivity. Typically, metals show a finite conductivity at ambient conditions, whereas the conductivity of nonmetals is close to zero. With this definition, 23 of the known chemical elements are nonmetals, and these are the subject of this text-book, namely hydrogen, boron, carbon, silicon, germanium, nitrogen, phosphorus, arsenic, the chalcogens, that is, oxygen through tellurium, as well as halogens and noble gases."

Antimony is thus classified by him as a metal. Yet, carbon and arsenic both of which show a finite conductivity at ambient conditions are classified by Steudel as nonmetals. This is puzzling.

2. Steudel continues:

"All nonmetals, however, show more or less pronounced semiconducting properties at elevated temperatures (depending on the size of the band gap). While the conductivity of metals decreases with temperature as thermal motion impedes the mobility of the electrons, semiconductors conduct electrical currents with less resistance at higher temperatures, that is, their conductivity rises. Indeed, the temperature dependence of electrical conductivity provides a more precise definition of metals and nonmetals."

This is an extraordinary passage in that Steudel is saying the temperature dependence of electrical conductivity provides a more precise definition of metals and nonmetals, than finite conductivity in ambient conditons.

His claim doesn't pass muster. Plutonium, widely recognized as a metal, exhibits increasing conductivity with temperature in the range –175 °C to +125 °C. This challenges the idea that temperature-dependent conductivity provides a more precise criterion for classification.

3. On a related note, the same passage in our Nonmetal article that cites Steudel (item 1 above) says:

"These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott..."

Yet graphite, a recognised nonmetal, also conducts electricity at absolute zero. This suggests that Mott’s definition, while elegant, is not definitive.

Update to lead image for Nonmetal article

A condensed periodic table highlighting nonmetals

widely recognized as a nonmetal

sometimes classed as a nonmetal

status as a nonmetal or metal unclear

The elements sometimes classed as nonmetals are at other times the six most commonly recognized as metalloids or borderline elements; all other elements are considered, or presumed to be, metals.

I’ve updated the legend for the lead image in the Nonmetal article so as to:

• bring the legend into alignment with the image;
• reflect a clearer, more neutral description of element classifications; and
• use citations where necessary but not excessively so.

The intent was to start with a clean classification, then explain the grey area separately. This approach is consistent with an encyclopaedic treatment; it also aligns with Wikipedia policy: avoid cramming too much interpretation into images or captions, and defer to the article text for deeper explanation.

The legend now reads as follows:

	Nonmetal	i.e., H, C, N, P, O, S, Se, F, Cl, Br, I, He, Ne, Ar, Kr, Xe, Rn
	Sometimes classed as a nonmetal	B, Si, Ge, As, Sb, Te
	Status as a nonmetal or metal unclear	At, Ts, Og

It has some accompanying text, with citations provided for the elements sometimes classed as nonmetals since their classification varies in the literature:

1. Hawley’s Condensed Chemical Dictionary (2016, p. 988) lists as nonmetals: H; B; C, Si, Ge; N, P, As, Sb; O, S Se, Te, Po; halogens; noble gases.
2. Vernon (2013), in the Journal of Chemical Education, lists the six elements most commonly recognised metalloids as B, Si, Ge, As, Sb, and Te.
3. Russell & Lee (2005, p. 419) treat As and Sb as metals.

All other elements are considered, or presumed to be, metals. No citations are included for:

• The nonmetals, as these are well-established in general chemistry literature and widely taught at the introductory level (WP:BLUE).

• The hazel-shaded elements, since the uncertainty of their classification is well acknowledged. No definitive status is asserted.

• All other elements considered, or presumed to be, metals. Describing both confirmed and inferred metallicity from periodic trends is standard and expected; “presumed to be” is careful phrasing that makes clear the inference.

The aim of this update is to improve clarity, reflect the consensus and ambiguity present in the literature, and provide citations where genuinely needed, without overburdening textbook-level facts.

Types

Classification schemes for nonmetals vary widely, with some recognizing as few as two subtypes and others as many as seven. For example, the Encyclopaedia Britannica periodic table recognizes noble gases, halogens, and other nonmetals.^[16] By contrast, seven of the twelve colour categories on the Royal Society of Chemistry periodic table include nonmetals.^[17][d]

Starting on the right side of the periodic table, three to four types of nonmetals can be recognized:

The boundaries between types are not sharp.^[i] Carbon, phosphorus, selenium, and iodine border the elements sometimes recognized as metalloids and show some metallic character, as does hydrogen.

Noble gases

Six nonmetals are classified as noble gases: helium, neon, argon, krypton, xenon, and the radioactive radon. In conventional periodic tables they occupy the rightmost column. They are called noble gases due to their exceptionally low chemical reactivity.^[18]

These elements exhibit similar properties, being colorlessness, odorlessness, and nonflammability. Due to their closed outer electron shells, noble gases possess weak interatomic forces of attraction, leading to exceptionally low melting and boiling points.^[39]

Chemically, the noble gases exhibit relatively high ionization energies, negligible or negative electron affinities, and high to very high electronegativities. The number of compounds formed by noble gases is in the hundreds and continues to expand,^[40] with most of these compounds involving the combination of oxygen or fluorine with either krypton, xenon, or radon.^[41]

Halogen nonmetals

Chemically, the halogen nonmetals exhibit high ionization energies, electron affinities, and electronegativity values, and are mostly relatively strong oxidizing agents.^[42] All four elements tend to form primarily ionic compounds with metals,^[43] in contrast to the remaining nonmetals (except for oxygen) which tend to form primarily covalent compounds with metals.^[j]

Unclassified nonmetals

Hydrogen behaves in some respects like a metallic element and in others like a nonmetal.^[48] Like a metallic element it can, for example, form a solvated cation in aqueous solution;^[49] it can substitute for alkali metals in compounds such as the chlorides (NaCl cf. HCl) and nitrates (KNO₃ cf. HNO₃), and in certain alkali metal complexes^[50][51] as a nonmetal.^[52] It attains this configuration by forming a covalent or ionic bond^[53] or by bonding as an ion to a lone pair of electrons.^[54]

Some or all of these nonmetals share several properties. Being generally less reactive than the halogens,^[55] most of them can occur naturally in the environment.^[56] Collectively, their physical and chemical characteristics can be described as "moderately non-metallic".^[57] When combined with metals, the unclassified nonmetals can form interstitial or refractory compounds.^[58] They also exhibit a tendency to bond to themselves, particularly in solid compounds.^[59] Additionally, diagonal periodic table relationships among these nonmetals mirror similar relationships among the metalloids.^[60]

Talk page nonmetal 1

Update to lead image legend
I’ve updated the legend for the lead image in the Nonmetal article so as to:

• bring the legend into alignment with the image;
• reflect a clearer, more neutral description of element classifications; and
• use citations where necessary but not excessively so.

The intent was to start with a clean classification, then explain the grey areas separately. I presume that’s ideal for an encyclopedic treatment. It also aligns with Wikipedia policy: avoid cramming too much interpretation into images or captions, and defer to the article text for deeper explanation.

The legend now reads as follows:

	Nonmetal	i.e., H, C, N, P, O, S, Se, F, Cl, Br, I, He, Ne, Ar, Kr, Xe, Rn
	Sometimes classed as a nonmetal	B, Si, Ge, As, Sb, Te
	Status as a nonmetal or metal unclear	At, Ts, Og

The legend has some accompanying text, with citations provided for the elements sometimes classed as nonmetals since their classification varies in the literature:

1. Hawley’s Condensed Chemical Dictionary (2016, p. 988) lists as nonmetals: H; B; C, Si, Ge; N, P, As, Sb; O, S Se, Te, Po; halogens; noble gases.
2. Vernon (2013), in the Journal of Chemical Education, lists the six elements most commonly recognised metalloids as B, Si, Ge, As, Sb, and Te.
3. Russell & Lee (2005, p. 419) treat As and Sb as metals.

As noted, all other elements are considered, or presumed to be, metals. No citations are included for:

• The nonmetals, as these are well-established in general chemistry literature and widely taught at the introductory level (WP:BLUE).

• The hazel-shaded elements, since the uncertainty of their classification is well acknowledged. No definitive status is asserted.

• All other elements considered, or presumed to be, metals. Describing both confirmed and inferred metallicity from periodic trends is standard and expected; “presumed to be” is careful phrasing that makes clear the inference.

The aim of this update is to improve clarity, reflect the consensus and ambiguity present in the literature, and provide citations where genuinely needed, without overburdening textbook-level facts.

Definition and applicable elements

Unless otherwise noted, this article describes the stable form of an element at standard temperature and pressure (STP).^[k]

Nonmetallic chemical elements are often broadly defined as those that mostly lack properties commonly associated with metals—namely shininess, pliability, good thermal and electrical conductivity (due to their band structure), and a general capacity to form basic oxides.^[63][64] There is no widely accepted precise definition;^[65] any list of nonmetals is open to debate and revision.^[66]

Seventeen elements are widely recognized as nonmetals:^[66][67]

Further, one or more of the following six elements are sometimes classed as nonmetals:

At other times, the elements are divided into three types: metals, metalloids, and nonmetals, where metalloids are regarded as intermediate in properties between metals and nonmetals.^[68] Among sources that adopt this classification, the six elements listed above are the ones most commonly recognised as metalloids.

Adding to the nuanced assessment of the nature of the elements near the traditional dividing line between metals and nonmetals, arsenic or antimony are occasionally instead classed as metals.

Thus, depending on the source, about 15–20% of the 118 known elements^[69] are classified as nonmetals.^[l]

Talk page nonmetal 2

Restoration and restructuring of "Suggested distinguishing criteria" section
A revised version of the "Suggested distinguishing criteria" section has been restored to the article. The original version was previously removed due to concerns about the inclusion of a timeline. The restored content omits the timeline and focuses solely on representative approaches to distinguishing nonmetals from metals, including single-property, two-property, and multi-property methods, concluding with a theoretical explanation via band structure, as provided by Ldm1954.

The band structure material, previously in section 5.5, has been relocated to the end of this section, where it fits more logically as a theoretical underpinning of the classification schemes discussed.

The structure of the revised section is as follows:

2 Suggested distinguishing criteria
  2.1 Single-property approaches
  2.2 Concerns about single-property approaches
  2.3 Density and electronegativity
  2.4 Multi-property classification
  2.5 Structure, quantum mechanics, and band theory

The section follows a logical progression from simple to more complex approaches, and from empirical observations to theoretical explanation. It has been rewritten for clarity, neutrality, and educational value.

Further feedback and improvements are welcome.

Structure, quantum mechanics, and band theory

The early terminologies were empirical categorizations based upon observables. As the 20th century started there were significant changes in understanding. The first was due to methods, mainly x-ray crystallography, for determining how atoms are arranged in the various materials. As early as 1784 René Just Haüy discovered that every face of a crystal could be described by simple stacking patterns of blocks of the same shape and size (law of decrements).^[72] Haüy's study led to the idea that crystals are a regular three-dimensional array (a Bravais lattice) of atoms and molecules, with a single unit cell repeated indefinitely. After Max von Laue demonstrated in 1912 that x-rays diffract,^[73] fairly quickly William Lawrence Bragg and his father William Henry Bragg were able to solve previously unknown structures.^[74][75][76] Building on this, it became clear that most of the simple elemental metals had close packed structures. With this determined the concept of dislocations originally developed by Vito Volterra in 1907^[77] became accepted, for instance being used to explain the ductility of metals by G. I. Taylor in 1934.^[78]

The second was the advent of quantum mechanics. In 1924 Louis de Broglie in his PhD thesis Recherches sur la théorie des quanta^[79] introduced his theory of electron waves. This rapidly became part of what was called by Erwin Schrödinger undulatory mechanics,^[80] now called the Schrödinger equation, wave mechanics or more commonly in contemporary usage quantum mechanics. While it was not so easy to solve the mathematics in the early days, fairly rapidly ideas such as the chemical bond terminology of Linus Pauling^[81] as well as electronic band structure concepts were developed.^[82]

From this the concept of nonmetals as "not-a-metal" originates. The original approach to describe metals and nonmetals was a band-structure with delocalized electrons (i.e. spread out in space). A nonmetal has a gap in the energy levels of the electrons at the Fermi level.^{[82]: Chpt 8 & 19} In contrast, a metal would have at least one partially occupied band at the Fermi level;^[82] in a semiconductor or insulator there are no delocalized states at the Fermi level, see for instance Ashcroft and Mermin.^[82] (A semimetal is similar to a metal, with a slightly more complex band structure.) These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott,^[83]: 257 and the equivalent definition at other temperatures is also commonly used as in textbooks such as Chemistry of the Non-Metals by Ralf Steudel^[84] and work on metal–insulator transitions.^[85][86]

Originally^[87][88] this band structure interpretation was based upon a single-electron approach with the Fermi level in the band gap as illustrated in the Figure, not including a complete picture of the many-body problem where both exchange and correlation terms matter, as well as relativistic effects such as spin-orbit coupling. For instance, the passivity of gold is typically associated with relativistic terms.^[89] A key addition by Mott and Rudolf Peierls was that these could not be ignored.^[90] For instance, nickel oxide would be a metal if a single-electron approach was used, but in fact has quite a large band gap.^[91] As of 2024 it is more common to use an approach based upon density functional theory where the many-body terms are included.^[92][93] Although accurate calculations remain a challenge, reasonable results are now available in many cases.^[94][95]

It is common to nuance the early definition of Alan Herries Wilson and Mott which was for a zero temperature. As discussed by Peter Edwards and colleagues,^[96] as well as Fumiko Yonezawa,^{[83]: 257–261}it is important to consider the temperatures at which both metals and nonmetals are used. Yonezawa provides a general definition for both general temperatures and conditions (such as standard temperature and pressure):^[83]: 260

When a material conducts and at the same time the temperature coefficient of the electric conductivity of that material is not positive under a certain environmental condition, the material is metallic under that environmental condition. A material which does not satisfy these requirements is not metallic under that environmental condition.

Band structure definitions of metals and nonmetals are widely used in current research into materials, and apply both to single elements such as insulating boron^[97] as well as compounds such as strontium titanate.^[98] The characteristics associated with metals and nonmetals in early work such as their appearance and mechanical properties are now understood to be consequences of how the atoms and electrons are arranged.

Dubious cites?

Good day Ldm1954,

In Archive 8 of this talk page, there is a thread titled Dubious cites (dated 5 August 2024), listing 21 items you posted, along with the comment: “Several inaccurate cites, they all need checking in detail.”

I’ve copied and pasted the 21 items below the horizontal rule, reviewed them, and provided an assessment of each. Of the 21, only two items—one clearly incorrect, and two partially incorrect (½ + ½ + 1)—can reasonably be considered dubious. This suggests that approximately 90% of your claims do not stand up to scrutiny.

For context, on 20 June 2024, I also assessed 18 edits you made to the Nonmetal article between 10 and 12 June 2024. That review found that just 1½ of those edits were valid, suggesting that roughly 91% were similarly unsupported.

Taken together, these two review exercises—covering 39 claims or edits with a 90% error rate—indicate a consistent pattern of questionable source-checking and editorial judgment. While good-faith editing is always appreciated, repeated issues of this kind—particularly when accompanied by strong editorial assertions—risk undermining the reliability of the article and diverting attention from more constructive improvements. At the very least, this pattern suggests a need for greater caution and more carefully considered contributions in the future. --- Sandbh (talk) 07:27, 17 April 2025 (UTC)

1. Cites of p7 in [21] for "brittle or crumbly" which source does not say. The only relevant information is a discussion of brittleness of nonmetallic materials such as MgO on p270.

   Yes, I agree, and updated the cite on 5 August 2024.

   As to your closing comment, cite 21 in fact states, "Most nonmetallic crystals are brittle at low temperatures but are quite ductile at elevated temperatures, i.e., T > 0.05T_m" (p. 291)

2. Cite of [26] for 1000 atom Se chains, where there is no source cited in the book so it is not a good source.

   The absence of a source in the book doesn’t necessarily make it "not a good source." In compendiums of this kind, it's not uncommon for authors to include observations without formal citation. In this case, the book was easily accessible and written by a physicist, so it seemed to be a reasonable tertiary source for the statement.

3. Cite of [68] for octet rule, where in fact the text says that is not a good approximation and VB should be used (changed)

   The paragraph in question explains a well-established generalisation—the tendency of nonmetals to gain electrons—by linking it to the stability of noble gas configurations, which is both chemically correct and accessible to a wide audience. As far as mention of the duet and octet rules goes, these are long-standing heuristic rules taught at an introductory level to explain why atoms gain or lose electrons. In the case of the noble gases, helium goes with the duet rule, and Ne through Rn with the octet rule.

   There is thus no need to delve into the theoretical underpinnings of chemical bonding via VB.

4. Both As & graphite are semimetals, incorrect statement in Enf

   The footnote in question was:

   "The solid nonmetals have electrical conductivity values ranging from 10⁻¹⁸ S•cm⁻¹ for sulfur to 3 × 10⁴ in graphite or 3.9 × 10⁴ for arsenic; cf. 0.69 × 10⁴ for manganese to 63 × 10⁴ for silver, both metals. The conductivity of graphite (a nonmetal) and arsenic (a metalloid nonmetal) exceeds that of manganese. Such overlaps show that it can be difficult to draw a clear line between metals and nonmetals."

   After your edit it read:

   "The solid nonmetals have electrical conductivity values ranging from 10⁻¹⁸ S•cm⁻¹ for sulfur to 3 × 10⁴ in graphite or 3.9 × 10⁴ for arsenic; cf. 0.69 × 10⁴ for manganese to 63 × 10⁴ for silver, both metals. The conductivity of graphite and arsenic (both semimetals) exceed that of manganese.

   The impact of your edit was to introduce confusion with mentions of "semimetals", and to undermine the point that, "it can be difficult to draw a clear line between metals and nonmetals."

5. The use of an O-level (< 16 years old) text book, i.e. Cambridge O Level Chemistry Book by B. Earl and Doug Wilford is dubious.

   This book represents a reliable source that is within grasp of the general reader. As such there is nothing dubious about it.

6. Citation to Sanderson 1957 quoted a page that did not exist (was the 1967 book meant?). In any case the ref has only been cited twice so removed as it is not really that relevant or accurate.

   The citation was to "Sanderson 1957, p. 229". The article in question is Sanderson J. Chem. Educ. 1957, vol. 34, no. 5, p. 229. The article is called, "An electronic distinction between metals and nonmetals". It is relevant given its subject matter.

7. Temperature coefficient of resistivity is very much older than the table implied, it is in Kittel 1956. Date moved to 1956 (it might be earlier) and a relevant source added. Other dates are probably wrong.

   I choose this 1999 source since it said:

   "Probably the best criterion for distinguishing a metal and a metalloid or semiconductor is the temperature coefficient of thermal and electrical conductivity. With increase in temperature, the thermal and electrical conductivity of a metal decreases, whereas that of a metalloid or semiconductor increases."

   As such, it is quite relevant. That said, Lanzetta and Gavignet (2011, p. 97) credit Sir Humphrey Davy, in 1821, with discovering, "that all metals have a positive temperature coefficient of resistance".

   Lanzetta F & Gavignet E 2011, Thermal measurements and inverse techniques, in Orlande et al. (eds), Thermal Measurements and Inverse Techniques, CRC Press, pp. 95–142

   Upon reflection, it would be better to list the 1821 entry for Davy, and to add a footnote pointing to the 1999 source.

8. Atomic conductance is just electrical conductance in different units; it is redundant so has been deleted.

   Atomic conductance is the conductivity of a block of the substance 1 cm² in cross-section but long enough to contain one mole of atoms of the element. It is a measure of the conductivity of one mole of atoms of the element. It is used by Hill G, Holman J & Hulme PG 2017, Chemistry in Context, 7th ed., Oxford University Press, Oxford, to classify the elements as metals, and as metalloids and nonmetals.

   As such, it is not redundant.

9. The article about "3D conductivity" was misquoted, it is just another rephrasing of the established conductivity argument. Deleted from table.

   Myers writes:

   "There is, of course, only one property which is common to all metals and sets them apart from nonmetals: high electrical conductivity in three dimensions [italics added]...Some texts are careful to point out that graphite is a good conductor of electricity (but this is only in two dimensions, along the planes of carbon atoms)..."

   As such there was no case for the deletion of the "3D conductivity" entry.

10. The claim in the table that Horvath connects critical temperature to metal/nonmetal does not appear in the paper. Hence removed from the table.

    Horvath's figure 1 shows a periodic table including a traditional dividing line between metals and nonmetals. He refers to this as a diagonal line although it has a stair step shape. He writes, "The elements allocated on the left side (metallic side) of the diagonal line, Al, Ge, Sb, and Po, show the highest critical temperatures in their groups (vertical columns of the periodic table)." See his figure 1. Horvath thus connects critical temperature to metal/nonmetal.

11. The cite of Remy (1956) as "Minimum excitation potential" is inaccurate. He gives the standard band structures explanation. Removed.

    Remy wrote:

    "Borelius (1939) has pointed out that all elements with minimum excitation potentials appreciably over 6 e.v. are non-conductors. Those with minimum excitation potentials in the neighborhood of 6 e.v. are semi-conductors, and those with excitation potentials significantly less are metals."

    There was thus no basis for removal.

12. The cite of Mann et al 2000 on configurational energy is invalid. The paper only discusses the d-block elements and makes no claims about metals versus nonmetals in general. The Wikipedia link also makes no such claims. Removed.

    Mann et al. write that, "metals have configuration energies lower than that of silicon, the least electronegative of the metalloids" and refer to "silicon, the least electronegative nonmetal (except for gold which has a CE equal to that of silicon)."

    Mann is thus not invalid and should've been retained.

13. Johnson (1966) does mention physical state, e.g. gas, but then says it is not so good and lists the other standards such as conductivity etc. Hence removed from table as unverified.

    Johnson writes:

    "The metallic or nonmetallic nature of an element is best [bold added] indicated by certain physical properties. The most obvious properties which help us to classify an element as a metal or nonmetal are its physical state, appearance, and malleability and ductility. All elements which are gaseous at room temperature are nonmetals. Liquid or solid elements may be metals or nonmetals…Solid nonmetals are either hard and brittle or soft and crumbly. Most metals, in contrast, are malleable and ductile. These readily apparent physical properties allow one to distinguish between most metals and nonmetals. [talics added] However, for a number of elements, particularly those in the vicinity of the semimetals in Figure 1-1, these properties do not provide an unambiguous classification and other properties must be considered."

    There was thus no basis to remove this citation.

14. Scott 2001 cites page 1781 which does not exist in any edition of the book (250–350 pages). Marked as dubious, perhaps delete later.

    Agree. This cite is erroneous and should be corrected or deleted.

15. Povh & Rosin 2017 has no statements about thermal conductivity on p131. There is a short description on p173, but it does not call this a defining property. Deleted as unverified.

    At p. 131, the authors write, "The high speed of electrons at the Fermi surface is again responsible for the roughly 100 times larger thermal conductivity of metals compared with nonmetals." There was thus no basis for deletion.

16. Brandt 1821, p5 is not even close to discussing metals and opacity. Deleted as very unverified and irrelevant.

    The actual name of the author, as listed in the Nonmetal article, is Brande. At page 5 he writes, "The metals, as a class, are characterized by a peculiar lustre and perfect opacity." The source is thus verifiable and relevant.

17. Beach 1911 appears to have been copied from Origin and use of the term metalloid which has unrelated information. Since this is a very long book, without specific page number etc this source is not verifiable.

    This source is easily verifiable via the Internet Archive. Exactly the same entry is found in the 1903 edition of Beach, here. See the entry for "Metalloid".

18. Harris 1803 provides the standard property list, the text misquoted what is stated.

    Harris says, "…specific gravity is greater than that of any other bodies yet discovered; that they are better conductors of electricity than any other body;"

    The quote said, "... [metals'] specific gravity is greater than that of any other bodies  yet discovered; they are better conductors of electricity, than any other body."

    There was thus no misquote, rather a single “that” was missing, which made no difference to the substance of the quote and which you could’ve easily added.

19. Cyclopaedia: Or an Universal Dictionary of Arts and Sciences (1743) rambles for three and a half pages with statements such as differentiating gold, mercury and silver by how much sulphur is in them, that metals are transmutable into each other etc -- there is a link to an open source. While the statement about "heaviness" is there, it is not the focus of the article. I cannot consider this as a useful source so I am deleting it, whereas Harris 1803 is definitively reputable.

    In its entry for METAL, the source writes "That which distinguishes metals from all other bodies ... is their heaviness ...”. There was thus no basis to delete it.

20. Jones citation is "Jones BW 2010, Pluto: Sentinel of the Outer Solar System" which is definitely not on distinguishing criteria of nonmetals. Marked for the moment as dubious.

    Jones discusses the role of classification in science. There was thus no basis to mark this citation as dubious.

21. Hare and Basche 1836 p310 is cited for inventor Humphry Davy made an important discovery that reshaped the understanding of metals and nonmetals. It says nothing like that on p310. Removed as unverified.

    It is common knowledge that Davy discovered the first of the alkali metals and that, astonishingly for the time, these were lighter than water. As Hare and Basche thus wrote on page 310:

    "Less than thirty years ago, the line of demarcation between metals and other bodies was easily drawn. There was then no known metal which had a specific gravity less than six; and of other bodies, none, of which the specific gravity was as high as five. But the discovery of alkalifiable metallic radicals, having a specific gravity less than that of water, annihilated [italics added] the barrier which had been established on the basis of superior gravity."

    Thus, there was no basis for removing the cite.

Historical confusion on chemical elements terminology is no longer relevant

I appreciate the idea of improving reference accuracy. However, it’s worth noting that many of the earlier concerns about citations—such as those listed in the “Dubious cites” thread—do not hold up to scrutiny. A recent review of 21 items found that only two were genuinely problematic, and a prior assessment of 18 edits produced a similar outcome. This suggests that most of the claims regarding citation inaccuracy were themselves unfounded.

That said, all editors are of course welcome to check and improve references as part of the normal editorial process. As I understand it, there is no precedent or procedural expectation in Wikipedia that disputed or allegedly inaccurate citations must be vetted by a third party before further editing proceeds. Genuinely dubious citations are normally dealt with through established editorial practices—either being removed, corrected, or queried using appropriate tags. Where relevant, the editor who originally added the citation may respond to a query or supply a replacement. This reflects Wikipedia’s collaborative and iterative editing model, rather than a formal arbitration system.

If there are still specific claims or citations under dispute, the talk page remains the appropriate venue for discussion. I presume that the way forward in improving the article—as has always been the case—rests on evidence, reliable sources, and presumptive consensus, without introducing unnecessary procedural barriers to progress.

Lead image for Nonmetal article

A condensed periodic table highlighting nonmetals

nonmetal

sometimes classed as a nonmetal

status as a nonmetal or metal as yet unconfirmed

The elements sometimes classed as nonmetals are at other times the six most commonly recognised as borderline elements or metalloids, with As and Sb occasionally classed as metals. All other elements are considered, or presumed to be, metals.

Sandbh, please stop

@Sandbh, sorry but you are again making unilateral changes based upon your own opinion which is not shared. Rather than attempting to seek consensus, for instance by making suggestions in a Sandbox, you are just deleting/editing. This is not how concensus is generated on Wikipedia, so please only make changes for which there is consensus. I am reverting your recent edits. Ldm1954 (talk) 15:45, 5 April 2025 (UTC)

@Ldm1954 I appreciate your concerns, but I’d like to clarify something about WP editing norms, as I understand them.

WP encourages bold editing—consensus is typically reached after edits are made, not beforehand. The WP:BRD cycle—bold, revert, discuss—is designed to allow exactly this kind of editing rhythm: if an edit is reverted, the next step is discussion, not a presumption that prior consensus was required.

Thus, consensus is not required before making an edit. If it were, the entire platform would grind to a halt. Wikipedia’s open model is built on the principle of “edit first, discuss if reverted.” Saying “consensus is required before editing” flips the model on its head.

In this particular case your single reversionary edit revereted seven of my edits: ;;;;;;

Of these edits of mine which you reverted:

#1 was reasonably reverted as you posted an explanation for it, thank you, on the Nonmetal talk page, here. Accordingly, I intend to take up the discussion there. The edit by me that you reverted was made in response to User:Headbomb's comment here: "This section is so wrong it needs to be rewritten / purged"

#2 undid the elimination of a redundant {{clear}} tag. Accordingly, I intend to re-revert.

#3 is associated with reversion #1, which I said I'd take up on the Nonmetal talk page.

#4 undid the elimination of a redundant {{clear}} tag. Accordingly, I intend to re-revert.

#5 undid a "dubious" tag removal, with the basis of the removal explained by me on the Nonmetal talk page, here. Accordingly, I intend to re-revert.

#6 undid some adjustments to the lead image legend notes, with result that the lead image and its legend notes are now mismatched. Accordingly, I intend to re-revert, and post a separate discussion to the Nonmetal talk page about the basis for the adjusted legend notes.

#7 undid the addition of a comma in the lead sentence of the article after, "In the context of the periodic table". As a grammatical improvement, I intend to re-revert. --- Sandbh (talk) 12:14, 13 April 2025 (UTC)

RfC on uses of the 23 nonmetals

Should this content on the uses of the 23 nonmetals be removed from the nonmetal article?

Considerations
1. WP:FAC criteria: Criterion 1b states that an FAC article is, "comprehensive: it neglects no major facts or details and places the subject in context".

2. Encyclopedic relevance: Content about the discovery of nonmetals has been part of the article since 2015. Throughout nine FAC nominations, there have been no objections or comments about its inclusion. After nearly a decade, it is unlikely that such content has suddenly become non-notable. Removing such information could be seen as knowledge censorship, which contradicts Wikipedia's principles.

3. Historical context: WP is an encyclopedia which means that it represents an organised compilation of collected facts. Given the subject matter of the nonmetal article, it follows that information about the discovery of the nonmetals is relevant. Indeed, there would be nothing to write about nonmetals but for their discovery. This includes the discovery of He off-planet; P as by-product of attempting to create the fabled philosopher's stone; and the discovery of F which killed some chemists along the way. These are notable items in the consolidated history of the discovery of nonmetals.

4. Discovery dates: The section is organised into two subsections:

• Nonmetals discovered before the concept chemical elements and nonmetals.
  
• Nonmetals discovered after these concepts were established.

This organisation provides clarity and context, showing the evolution of understanding regarding nonmetals.

5. Discovery methods: The discovery dates are accompanied by the methods used, where known. This is significant as it highlights patterns, such as:

• noble gases primarily extracted from air;
• halogens discovered via their halides;
• the variegated unclassified nonmetals via equally variegated methods; and
• nonmetals sometimes called metalloids via thermal extraction.

Expecting the general reader to piece together this knowledge from 23 separate articles is impractical and non-encyclopedic. This section consolidates important information for easier comprehension.

6. List-like content: The content of the section is to some degree list-like, as can be found in sections of numerous Wikipedia articles.

!Votes
Oppose removal. --- Sandbh (talk) 12:39, 23 July 2024 (UTC)

Nonmetals sometimes counted as metalloids

The six elements most commonly recognized as metalloids—boron, silicon, germanium, arsenic, antimony, and tellurium—are sometimes instead counted as nonmetals. In the periodic table, they occupy a diagonal region within the p-block extending from boron at the upper left to tellurium at the lower right, along the notional dividing line between metals and nonmetals shown on some tables.^[10]

They all have a metallic appearance, and are brittle and poor-to-good conductors of heat and electricity. Specifically, boron, silicon, germanium, and tellurium are semiconductors. Arsenic and antimony have the electronic band structures of semimetals, although both have less stable semiconducting allotropes: arsenic as arsenolamprite, an extremely rare naturally occurring form;^[99] and antimony in its synthetic thin-film amorphous form.^[10][100]

Chemically, such elements generally behave like weak nonmetals. Among the nonmetals they tend to have the lowest ionization energies, electron affinities, and electronegativity values, and are relatively weak oxidizing agents. Additionally, they tend to form alloys when combined with metals.^[10]

It is not relevant whether elemental nonmetals are sometimes called metalloids. Metalloids are a different topic, and should only be cross-referenced and/or in a "See also". Otherwise this is coatracking. 

"Metalloids" --> "Nonmetals sometimes counted as metalloids"; ce accordingly

Talk 2

Thanks for clarifying your points. I acknowledge several uses of the term "nonmetal." However, it’s important to note that the Wikipedia nonmetal article has already established its scope clearly with its hatnote...

"This article is about the chemical elements that are not metals. For other meanings, see Nonmetal (disambiguation)."

...and the first sentence of the lede:

In the context of the periodic table a nonmetal is a chemical element that mostly lacks distinctive metallic properties.

This hatnote and statement are intended to define the article's focus on nonmetals within the context of chemistry.

Re "There are four main uses of the words

1. Nonmetallic elements, referring to the periodic table.

2. Everything that is not a metal, the standard use in research articles and 21st century science. Definition is based upon electrical conductivity.

3. Astronomy, probably because of Kirchhoff & early solar spectroscopy.

4. Venacular, shiny stuff for cars etc."

1. 1: No, the overwhelming popular use is the term "nonmetal". I invite you to provide evidence to the contrary.
2. 2: Please provide evidence of such prevalent standard use, and that such standard use is based on electrical conductivity. By this criterion, graphite, which has a conductivity of up to 3 × 10⁴ S•cm⁻¹ would be a metal. See: Jenkins GM & Kawamura K 1976, Polymeric carbons—carbon fibre, glass and char, Cambridge University Press, Cambridge, p. 88.
3. 3: Agreed
4. 4: Please provide evidence of such use in reliable sources.

Sandbh (talk) 14:21, 18 July 2024 (UTC)

Talk

Thanks for sharing your perspective. I feel there may be some misunderstandings that we can clarify.

Firstly, I don't recall making a statement equating nonmetal=non-metal=not a metal. If you could provide specifics on this, it would help me understand your concern better. For instance, in our previous discussion, you mentioned, "And, of course, 'non-metal' is the same as 'nonmetal' which is also the same as 'not a metal.'" Well, no, "nonmetal" is not necessarily the same as "not a metal." Arsenic, commonly regarded as a nonmetal, is considered a metal from an electronic band structure perspective and sometimes as a full-blown metal.

It's important to acknowledge that there isn’t a unified popular concept of a nonmetal across all scientific disciplines. For example, a theoretical physicist colleague recently mentioned that "Astronomers, Physicists, Chemists are sitting in different bubbles. Each bubble has its own language." Philip Ball, past editor of Nature, in a Chemistry World article posted on July 11th, refers to "today’s era of siloed disciplines".

Given this lack of a unified conception, the term "nonmetal" most commonly refers to chemical elements that mostly lack distinctive metallic properties. I understand that there are other meanings, but these are not as prevalent.

Regarding the opinions of others, I strive to consider them when they align with the state of the literature and WP policies and guidelines. I believe my suggestions for acknowledging other meanings of the term "nonmetal," such as updating the disambiguation page, reflect this effort.

Discovery of applicable elements

While the concept of a chemical element came to fruition during the 18th and 19th centuries, some elements now classified as nonmetals (or sometimes as metalloids) were known and used from as early as antiquity, even if they were not recognized as such at the time.

Disambig

ping|Ldm1954 I agree WP works via consensus, and strive to accommodate the opinions of other editors when they are consistent with WP policies, guidelines, and the literature. I acknowledge the existence of less common uses of the term "nonmetal". That is why the nonmetal article includes a hatnote saying:

"This article is about the chemical elements that are not metals. For other meanings, see Nonmetal (disambiguation)."

Having established the scope of the article, which is about the the most frequent conception of what a nonmetal is, I feel that the first sentence of the lede should remain straightforward and focused on this scope:

"A nonmetal is a chemical element that mostly lacks distinctive metallic properties."

This approach ensures clarity for readers while respecting the article's defined scope.

I suggest the infrequent use of the term "nonmetal" to refer to e.g. AgBr, NiO, and paraffin wax be mentioned in the Nonmetal (disambiguation) page. For example, by adding the following entry:

• Insulating compounds, e.g. silver bromide, diamond, or paraffin wax

Nonmetal organisation

• Sorry, but I think prefer the current organization of pages. It seems more useful for navigation, and more aligned with WP conventions. With this list, there are multiple problems:

  • I still think #2 and #3 are the same definition, or at least close enough to be discussed in the same entry. And most likely they should be discussed together with the more amorphous definition of a "nonmetallic material", which may also include considerations of mechanical properties, not only conductivity.
  • Hatnotes are mostly unhelpful here. Absolute zero or materials science are not useful for the reader interested in this topic.
  • Some entries rely on long quotations, which is not not the preferred style. In contrast, the dab page entries do not need to define the subject exhaustively and can be kept short.
  • The title "Nonmetallic material" seems more natural than "List of nonmetal meanings". Also I think it is better to focus on the concept (the class of materials), and not on the terminology. Of course terminology is important in order to establish boundaries on what to include in the article, but it is not usually the central topic. Currently the article Nonmetallic material also focuses heavily on terminology, but I think that can be fixed.

  Jähmefyysikko (talk) 12:15, 12 July 2024 (UTC)

ping|Jähmefyysikko Thanks for your further thoughts.

The current organisation of pages (which is fragmented) alongside the proposed organisation is:

^ sharpened focus

The current organisation is fragmented since related information is spread across different pages. The proposed organisation streamlines navigation by centralising different meanings of nonmetals into a single "List of nonmetal meanings" page. This approach reduces fragmentation and provides a clearer pathway for users to find the specific context they are interested in.

The "sharpened focus" qualifier for Nonmetallic material means that e.g. the content re nonmetals in astronomy should be removed. This is because "nonmetallic material" has a specific meaning in a materials science context, one that has no relation to nonmetals in astronomy.

As far as WP conventions go, the proposed list is a Wikipedia: Stand-alone list. I've edited it to make its appearance more consistent with such a list, such as Lists of mathematics topics.

Re your list of multiple problems:

• I understand your point about the related nature of #2 and #3. However, combining these definitions might lead to an overly complex entry for the general reader. I feel it's important to distinguish the broader category of semiconductors and insulators from the specific condition of conductance approaching absolute zero. Regarding nonmetallic materials, discussing their mechanical and other properties alongside electrical characteristics would indeed create a "too much information" omnibus entry. For clarity and ease of understanding, I suggest keeping these entries distinct.
• The wikilinks in the article are the best currently available, as far as I could discern. I agree they aren't really useful to the reader. In a sense they're the equivalent of red links. They represent an invitation to add more relevant content to the article at the end of the wikilink or to hive off the same into a new article.
• There's no preferred style that I know of; the quotations are there to illustrate usage of the term in the literature.
• The title, "Nonmetallic material" would not work since "nonmetallic materials" excludes gases.

List of nonmetal meanings

The term nonmetal has several meanings, listed from general to more specific, as follows:

• Chemical elements that mostly lack the distinctive characteristics of metals. This is the definition found in most dictionaries.^[112]
  
• A semiconductor or insulator. These are materials (or gases) that do not conduct electricity as well as metals.
• A material in which electrical conductivity tends to zero at a temperature of absolute zero.
  
• In astronomy, the elements hydrogen and helium. In this context, all other elements prevalent in stars and interstellar space are regarded as metals.
  

A related term is nonmetallic material which refers to solid and liquid compounds and elements that do not exhibit the properties of metals. These materials include ceramics, polymers, and possibly some composites.^[113]

Uses

The individual uses of each of the 23 non-metallic elements can be aggregated into 13 types, shared by many, a signficant number or a few of the elements concerned.

Many of these elements have uses in household accoutrements;^[1][a] medicine and pharmaceuticals;^[2] and lasers and lighting.^[3] They are components of mineral acids;^[4] and prevalent in plug-in hybrid vehicles;^[5] and smartphones.^[6]

A significant number have attenuative and agricultural applications. They are used in lubricants^[7]; and flame retardants and fire extinguishers.^[8] They can serve as inert air replacements, such as fluorine in SF₆;^[9] and are used in cryogenics and refrigerants.^[10] Their significance extends to agriculture, through their use in fertilizers.^[11]

Additionally, a smaller number of nonmetals find specialized uses in explosives;^[12] and welding gases^[13], including carbon (in CO₂).

• 
  Nitric acid (here colored due to the presence of nitrogen dioxide) is often used in the explosives industry^[14]
• 
  A high-voltage circuit-breaker employing sulfur hexafluoride (SF₆) as its inert (air replacement) interrupting medium^[15]
• 
  A COIL (chemical oxygen iodine laser) system mounted on a Boeing 747 variant known as the YAL-1 Airborne Laser
• 
  Cylinders containing argon gas for use in extinguishing fire without damaging computer server equipment

Nonmetal and related meanings (inc. electrochemistry)

I'd've thought that physics would've referred to nonmetals as semiconductors or insulators but it turns put that this instead occurs in electrochemistry (see meaning 2 below, 1973).

For reference, please find hereafter a summary of the five to six "nonmetal or related" meanings in 1. metallurgy; 2. chemistry; 3. astronomy; 4. physics; and 5. materials science. I’ve included extracts from the literature, where possible.

The entries are arranged in chronological order of (loosely) either their field or the earliest date from which the applicable notion seems to have originated.

Corrections and clarifications welcome.

--- Sandbh (talk) 08:30, 6 July 2024 (UTC)

Feedback requested on tentative proposal

{ping|YBG|Ldm1954|Johnjbarton|Double sharp}

I'm not an expert in the nonmetal field, but I've developed my understanding of the relevant and related literature to the point where I feel I can propose a potential way forward, considering recent discussions.

In this context, I suggest creating a list article with the following title:

List of nonmetal and related meanings

The contents would include:

Nonmetal in general use

Draft summary: "Nonmetals are chemical elements that mostly lack the distinctive characteristics of metals. They are usually poor conductors of heat and electricity and have high ionization energies and electronegativities."

Link: Nonmetal

Nonmetal in physics

Draft summary: To be further developed, based on current content in Nonmetallic materials.

Link: Not currently applicable

Nonmetal in astronomy

Draft summary: "In astronomy, nonmetals refer to hydrogen and helium, all other elements prevalent in stars and interstellar space being regarded as metals."

Link: Nonmetal (astronomy) —> Metallicity

Nonmetal in metallurgy

Draft summary: "When distinguishing nonmetals from metals, the latter are characterised by the presence of free electrons in their structures, and electrical conductivity decreasing when temperature decreases. Chemically, metals have alkaline hydroxides. More broadly, nonmetals include structural plastics, structural ceramics, and possibly metal-nonmetal composites."

Link: Not currently applicable

Comment: The source is, Chandler H (ed.) 1998, Metallurgy for the Non-metallurgist, ASM International, Materials Park. OH, pp. 242, 154:

metal. (1) An opaque lustrous elemental chemical substance that is a good conductor of heat and electricity and, when polished, a good reflector of light. Most elemental metals are malleable and ductile and are, in general, denser than the other elemental substances. (2) As to structure, metals may be distinguished from nonmetals by their atomic binding and electron availability. Metallic atoms tend to lose electrons from the outer shells, the positive ions thus formed being held together by the electron gas produced by the separation. The ability of these "free electrons" to carry an electric current, and the fact that this ability decreases as temperature increases, establish the prime distinctions of a metallic solid. (3) From a chemical viewpoint, an elemental substance whose hydroxide is alkaline. (4) An alloy.

Nonmetals...include structural plastics, structural ceramics, and possibly metal-nonmetal composites...

Nonmetallic materials in materials science

Draft summary: "In materials science, nonmetallic materials encompass solid and liquid compounds and elements that do not exhibit the properties of metals. These materials include ceramics, polymers, and certain composites."

Link: Materials science, with some mention of the five types of engineering materials other than "Metals and alloys", and several relevant citations mentioning "nonmetallic materials".

This proposal would involve:

• deleting Nonmetal (disambiguation);
  
• retitling Nonmetallic materials to List of nonmetal and related meanings; and
  
• adjusting and reusing some of the existing content of Nonmetallic materials.

I'm particularly conscious of the work that Ldm1954 has put into Nonmetallic materials which, in a roundabout way, may well turn out to be quite useful.

I'd appreciate any feedback or suggestions on this proposal. — Sandbh (talk) 08:28, 3 July 2024 (UTC)

Ldm

In a nonmetal, electrical conductivity approaches zero as the temperature approaches absolute zero. Conversely, metals maintain a finite conductivity at absolute zero. This difference can be explained by their electronic band structures: nonmetals have energy bands that are fully occupied or completely vacant, whereas metals have at least one band that is partially occupied.^[16]

These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott^[17] and can also be found in chemistry textbooks such as Chemistry of the Non-Metals by Ralf Steudel.^[18]

Zabet-Khosousi J & Dhiriani A-A 2011, Coupling in metallic nanoparticles: Approaches to optical nanoparticles, in Sattler KD, Handbook of Nanophysics: Nanoparticles and Quantum Dots, p. 25-2

Band structure definitions of metallicity are the most widely used, and apply both to single elements such as insulating boron^[19] as well as compounds such as strontium titanate.^[20] (There are many compounds which have states at the Fermi level and are metallic, for instance titanium nitride.^[21]) There are many experimental methods of checking for nonmetals by measuring the band gap, or by ab-initio quantum mechanical calculations.^[22]

Relevant meanings

I am posting this for discussion, having for some time worked on it in the background. I feel it's now in a form that's suitable for further consideration.

My impression is that there are three types of relevant and distinguishable meanings associated with the term "nonmetal": 1. metal (inc. in physics); 2. nonmetal; 3. nonmetallic material. These three types seem to imply the existence of an undocumented type: 4. nonmetallic substance.

Types
1. "Metal", in the general use meaning of the term, refers to a class of elements and their alloys generally characterized by high electrical and thermal conductivity, malleability, ductility, and lustre, and their capacity, as elements, to form positive ions. This general meaning is what most people understand and use in everyday language and in many practical applications. I appreciate that "postive ions" is not what most people would understand about metals. That said, in the ten dictionaries I looked up the definition of "metal", six of them included a reference to chemical properties.

There are some niche meanings of the term metal, in physics and in astronomy, but apparently not in metallurgy (strangely enough):

a. In physics, a metal is a solid with a Fermi surface at zero temperature. Only metals conduct electricity at this temperature.

b. In astronomy, the situation is complicated:

Stellar interior specialists use 'metals' to designate any element other than hydrogen and helium, and in consequence ‘metal abundance’ implies all elements other than the first two. For spectroscopists this is very misleading, because they use the word in the chemical sense. On the other hand, photometrists, who observe combined effects of all lines (i.e. without distinguishing the different elements) often use this word 'metal abundance', in which case it may also include the effect of the hydrogen lines.

See: Jaschek C & Jaschek M 1990, The Classification of Stars, Cambridge University Press, Cambridge, p. 22

c. In metallurgy, one would think there would be a generally agreed meaning or definition of a metal, but there isn’t, from what I could find.

2. "Nonmetal", in the general use meaning of the term, is a chemical element mostly lacking distinctive metallic properties.

a. In 1996, the physicist Nevill Mott said that at T = 0, a nonmetal doesn't conduct (whereas a metal does). The earliest reliable source mentioning this seems to be Davis EA 1998, Nevill Mott: Reminiscences And Appreciations, CRC Press, Boca Raton, p. 255.

b. One would think that in physics—given the widely-recognised trichotomy of metal, semiconductor, and insulator—that there would be a generally agreed meaning or definition of "non-metal" as a semiconductor or an insulator, but there isn’t from what I could find.

3. "Nonmetallic materials", in materials science, are substances in the condensed state (liquid, solid, colloidal) designed or manipulated for technological ends. Gases are generally not included here unless designed or manipulated etc. An explanation for the exclusion of gases is given by the Aims & Scope statement for Nature Materials:

Nature Materials is a monthly multi-disciplinary journal aimed at bringing together cutting-edge research across the entire spectrum of materials science and engineering. Materials research is a diverse and fast-growing discipline, which has moved from a largely applied, engineering focus to a position where it has an increasing impact on other classical disciplines such as physics, chemistry and biology. Nature Materials covers all applied and fundamental aspects of the synthesis/processing, structure/composition, properties and performance of materials, where "materials" are identified as substances in the condensed states (liquid, solid, colloidal) designed or manipulated for technological ends."

So, there it is: gaseous substances are out of scope of "materials", unless they are "designed or manipulated for technological ends". The term "nonmetallic material: then becomes somewhat of an artificial distinction, rather than a properties-based one.

Eleven extracts from the literature illustrating the use of the term "nonmetallic materials" can be found here.

4. "Nonmetallic substances" are solids, liquids and gases, other than metals. Curiously, there is no unified notion of such a type in the literature, from what I could find. It includes the type 2a non-extant meaning of semiconductors and insulators; and the type 3 meaning of nonmetallic materials.

Nonmetallic materials

I've been looking into conceptions of "nonmetallic materials". Most curiously, gases like H, N and O are generally out of scope, unless designed or manipulated for technological ends (never mind their status as nonmetals).

Weird, eh? The explanation is give by the Aims & Scope statement for Nature Materials:

"Nature Materials is a monthly multi-disciplinary journal aimed at bringing together cutting-edge research across the entire spectrum of materials science and engineering. Materials research is a diverse and fast-growing discipline, which has moved from a largely applied, engineering focus to a position where it has an increasing impact on other classical disciplines such as physics, chemistry and biology. Nature Materials covers all applied and fundamental aspects of the synthesis/processing, structure/composition, properties and performance of materials, where "materials" are identified as substances in the condensed states (liquid, solid, colloidal) designed or manipulated for technological ends."

So there it is: gaseous substances are out of scope of materials science, unless they are "designed or manipulated for technological ends". The term "nonmetallic material" in the case of gaseous substances, is an artificial distinction, rather than a properties-based one.

What follows are eleven extracts from the literature. Note that while compounds and nonmetal elements are mentioned, only the solid nonmetals get a seat at the table, being C, P and S in these examples. Quote #9 is interesting since it recognises O as a nonmetallic element but presumably not as a nonmetallic material.

   FRP   Fiber-reinforced plastic
   NR    Natural rubber
   SIC   Silicon carbide

   Diabon       Graphite                    Sigri, Germany

Dictionary definitions 2

1. Merriam-Webster Dictionary (2024)
   Defines a nonmetal as a chemical element that lacks the characteristics of a metal.
2. Collins English Dictionary (2024)
   Refers to chemical elements that form negative ions, have acidic oxides, and are poor conductors.
3. Cambridge Advanced Learner's Dictionary & Thesaurus (2024)
   Defines a nonmetal as a chemical element that is not a metal.
4. The Chambers Dictionary (1998)
   States that a nonmetal is an element that is not a metal.
5. MacMillan English Dictionary for Advanced Learners (2012)
   Defines nonmetals as chemical elements that are not metals, specifically mentioning that they are solids and gases and poor conductors.
6. Random House Webster's Unabridged Dictionary (2001)
   Defines nonmetals as elements like carbon or nitrogen, and mentions their inability to form simple positive ions.
7. The American Heritage® Dictionary of the English Language, Fifth Edition (2022)
   States that nonmetals lack the physical and chemical properties of metals.
8. Oxford English Dictionary (1989)
   Defines nonmetals as non-metallic elements.
9. Webster's New World College Dictionary (2014)
   Refers to nonmetals as elements lacking the characteristics of a metal.
10. Oxford English Dictionary (2003)
    Includes non-metallic elements or substances, but this broad definition is not consistently supported by the historical quotes provided:

Historical quotes set out in the Oxford English Dictionary

1857. "In Prussian blue..iron in part acts as a metal, in part acts as a non-metal, as if it replaced both the sodium and the chlorine of common salt." G. Wilson in Edinburgh Essays 340

1866. "The chlorides of the metals, like those of the non-metals, must also be divided into monochlorides." W. Odling, Lectures on Animal Chemistry 14

1871. "The number of the metals is much larger than that of the non-metals." Roscoe Elem. Chem. 6

1933. "The earliest attempts to measure the conductivity of the non-metals showed that it is about fifty times less than that of the metals." A. W. Barton, Text Book on Heat xiv. 325

1966. "One aspect of importance is the occurrence of many of the true non-metals in these two short periods." C. R. Tottle, Science of Engineering Materials i. 14

1995. "Some meteorites—‘stony-irons’—contain metal and non-metal components." Focus August 54/4

Five of six of the quotes refer to non-metal elements rather than non-metallic elements or substances.

Conclusion
A sizeable majority of dictionary definitions (close to 10 out of 10) support a primary use meaning of "nonmetal" as an element that is not a metal.

Dictionary defintions

1. Merriam-Webster Dictionary
a chemical element (such as boron, carbon, or nitrogen) that lacks the characteristics of a metal

2. Collins English Dictionary
any of a number of chemical elements that form negative ions, have acidic oxides, and are generally poor conductors of heat and electricity

3. Cambridge Advanced Learner's Dictionary & Thesaurus
noun   CHEMISTRY   specialized
a chemical element that is not a metal

4. The Chambers Dictionary (1998)
an element that is not a metal

5. MacMillan English Dictionary for Advanced Learners (2012)
Noun Chemistry
a chemical element that is not a metal, for example CARBON or oxygen. Nonmetals are SOLIDS and gases and are not good CONDUCTORS of heat and electricity.

6. Random House Webster's unabridged dictionary 2001
n. Chem. 1. having the character of a metal, as carbon or nitrogen. 2. an element incapable of forming simple positive ions in solution

7. The American Heritage® Dictionary of the English Language, Fifth Edition

n. Any of a number of elements, such as oxygen or sulfur, that lack the physical and chemical properties of metals.

8. Oxford English Dictionary, 2nd ed. (1989)
A non-metallic element. 1866 Odling Anim. Chem. 14 The chlorides of the metals, like those of the non-metals, must also be divided into monochlorides. 1871 Roscoe Elem. Chem. 6 The number of the metals is much larger than that of the non-metals.

9. Webster's New World College Dictionary
Any of those elements lacking the characteristics of a metal; specif., any of the electronegative elements (e.g., oxygen, carbon, nitrogen, fluorine, phosphorus, sulfur) whose oxides form acids and stable compounds with hydrogen.

10. Oxford English Dictionary (2003)
A non-metallic element or substance.

1857 In Prussian blue..iron in part acts as a metal, in part acts as a non-metal, as if it replaced both the sodium and the chlorine of common salt. G. Wilson in Edinburgh Essays 340

1866 The chlorides of the metals, like those of the non-metals, must also be divided into monochlorides. W. Odling, Lectures on Animal Chemistry 14

1933 The earliest attempts to measure the conductivity of the non-metals showed that it is about fifty times less than that of the metals. A. W. Barton, Text Book on Heat xiv. 325

1966 One aspect of importance is the occurrence of many of the true non-metals in these two short periods C. R. Tottle, Science of Engineering Materials i. 14

1995 Some meteorites—‘stony-irons’—contain metal and non-metal components. Focus August 54/4

Comments by Sandbh: Close to 10 out of 10 definitions support the primary use meaning of nonmetal as an element that is not a metal. Meaning #10 is not supported by the accompanying quotes, four of five of which are referring to nonmetal elements, rather than nonmetallic elements and substances.

The 1857 and 1866 quotes are for nonmetal elements.

For the 1933 quote, Barton earlier writes, "We may speak of metals and non-metals, but there are certain elements, such as tellurium and selenium, which it is difficult to assign to one class or the other." Quite cleary then, the author was referring to nonmetals as elements.

For the 1966 quote, the reference to true non-metals in the two short periods is a reference to the two short periods of the periodic table.

The 1995 quote appears to be a reference to the composition of stony metorites as 10–25% nickel-iron alloy, 75–90% silicon-based minerals, and trace amounts of iron sulfide. --- Sandbh (talk) 07:12, 23 June 2024 (UTC)

Uses

In the context of the nonmetal article, this table compares the main uses of metals and nonmetals. Frex, nearly all metals have uses in electronics and metallurgy. The table is based on the elements up to uranium.

For the metals, "Metallurgy" includes any application where metals are used in their primary form or processed into alloys, components, or structures for various industrial purposes.

Still on the metals, "Medical" covers implants and prosthetics; surgical instruments; diagnostic equipment; dental applications; medical devices (pacemakers, stents, defibrillators); radiation therapy; pharmaceuticals; orthodontics; biomaterials; laboratory equipment (centrifuges, incubators, autoclaves).

In terms of the broad contours of the situation, there are no surprises that I can see, with metal uses being based on their conductivity and structural strength; and the nonmetals being used for their semiconducting properties, and their biogenic properties. I guess the frequency of uses of metals in ceramics and glass production includes the capacity of transition metals to form coloured compounds.

I intend to update the nonmetal article accordingly in due course.

Johnjbarton

Thanks Johnjbarton for staying the course. Some context and clarification follows.

The nub of the problem is the "Nonmetallic compounds and elements" article. I'm not referring to its title, per se, but rather its confusing overlap with the "Nonmetal" article and other extant articles, as well as its lack of notability. There is no unified concept in the literature of the term "Nonmetallic compounds and elements."

In literature and scientific contexts, the term "nonmetal" primarily refers to chemical elements that lack metallic properties.

For example, I can go into a bookstore and find books for the general reader dealing with the periodic table, such as Sam Kean's best-selling The Disappearing Spoon and Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements, which employs the primary meaning of the term nonmetal. However, I cannot find any consolidated sources dealing with "Nonmetallic compounds and elements."

Regarding the title of the "Nonmetal" article, from 2013 to date, 46 editors have reviewed the article in the course of one GA nomination, two peer reviews, and nine FAC nominations (attracting 11 supports). Not one of these editors raised any concern about its title.

I've been editing the article since 2013, during which time it may have been viewed approximately 1,000,000–1,500,000 times. During this period, no concerns about the article title have been raised.

In this context there is no "out of the blue" sudden renaming requirement, as if all previous editors and viewers were asleep at the wheel.

It’s also worth noting that normal people typically don't use the term "nonmetal," and certainly not in normal conversations. OTOH, Wikipedia’s responsibility is to provide clear, accurate information based on established scientific usage.

The obvious solution is to retain the "Nonmetal" article as it stands, given the availability of sources and established usage.

To address the context-dependent nature of the term, we should use the "Nonmetal (disambiguation)" page to clearly differentiate its use in other fields, linking to relevant articles where these uses are discussed (e.g., "Metallicity" for astronomy).

The content of the "Nonmetallic compounds and elements" article should be merged into other applicable articles to avoid redundancy and confusion.

My interest here is in abiding by WP policy and respecting the primary use of the term nonmetal, which is widely recognized, used and written about in the context of chemical elements.

Ldm1954

As mentioned I've reviewed the edits made to the article during the period 10 to 12 June 2024 by Ldm1954.

Italics = summary; A = assessment

Nonmetal (disambig)

Look up nonmetal or non-metal in Wiktionary, the free dictionary.

Nonmetal may refer to:

• Nonmetal, a chemical element characterized by relatively low density and high electronegativity such as silicon, phosphorus, chlorine and argon
• Nonmetal (astronomy), the elements hydrogen or helium, with all others being regarded as metals
• In chemistry, a chemical substance or mixture lacking a predominance of metallic properties, such as water (H₂O), carbon dioxide (CO₂), or table salt (NaCl)
• In materials science, all substances which are not metals or alloys, including biomaterials, ceramics, composite materials, polymers, and semiconductors
• In physics, a substance with an electronic band gap; or which would not conduct electricity at a temperature of absolute zero; or the insulator in a metal-insulator transition.

See also

• All pages with titles beginning with Nonmetal
• All pages with titles beginning with Non-metal
  • absolute zero
  • biomaterial
  • ceramic
  • chemical substance or mixture
  • composite material
  • electronic band structure
  • metal-insulator transition
  • polymer
  • semiconductor

This disambiguation page lists pages associated with the title User:Sandbh/sandbox.
If an internal link incorrectly led you here, you may wish to change the link to point directly to the intended page.

A fly in the ointment: WP article title conventions

Notwithstanding everyone's good intentions, there is WP:TITLEDAB, which provides as follows:

"As a general rule, when a topic's preferred title can also refer to other topics covered in Wikipedia:

1. If the article is about the primary topic to which the ambiguous name refers, then that name can be its title without modification, provided it follows all other applicable policies.
2. If the article is not about the primary topic for the ambiguous name, the title must be disambiguated."

Now, the term "Nonmetal" is most frequently understood in the context of chemistry and the periodic table of elements. This being so, Nonmetal becomes the primary topic, as is currently the case. All other nonmetal-related articles must be disambiguated, including (where appropriate) via the use of brackets.

There's no need to type in brackets. Entering "nonmetal" into the Search Wikipedia box gives the following drop-down list:

Nonmetal

Nonmetallic compounds and elements

Nonmetal mining

Nonmetal (astronomy)

Nonmetallic cable

Nonmetal (disambiguation)

Non-metallic inclusions

Non-metallic cable

Non-metalliferous deposit

Non-metalic cable

As far as the Nonmetal article goes, I've edited the hatnote to read:

This article is about the chemical elements. For other uses, see Nonmetal (astronomy) and Nonmetal (materials science and physics).

Consolidated proposal for nonmetal article names

Ldm1954|King of Hearts|YBG|Johnjbarton

I suspect the following proposal could sort out the current mess, having regard to the general reader:

This structure helps clarify the different contexts in which the term "nonmetal" is used, making it easier for readers to find the specific information they need.

Sources and extraction proceses

Nonmetallic elements can be broadly categorized according to their sources and extraction methods. The first three categories below encompass the nine of the 23 nonmetallic elements that are uniquely light enough, or form compounds that are light enough, to be extracted from either natural gas or liquid air. ^[23]

The extraction processes that follow are shared with some metals:

Uses2

Nonmetals exhibit a broad range of uses due to their diverse chemical and physical properties. From essential roles in biology and industry to specialized applications in technology and everyday household items, nonmetals demonstrate a unique versatility that sets them apart from metals. This diversity not only underscores the cohesive nature of nonmetals as a group but also highlights the wide array of applications that make them indispensable in various fields.

Characteristic

Nonmetals are characteristically used as or in insulators, acids, biology, light emission and photonics, semiconductors, and inert atmospheres and shielding gases. Nonmetals such as nitrogen, oxygen, and sulfur are widely used as insulators due to their poor electrical conductivity. For instance, nitrogen and sulfur compounds are used as insulating materials in various industrial processes. This property is a direct consequence of nonmetals' tendency to form covalent bonds, which do not allow free movement of electrons as metals do. Many nonmetals are fundamental in forming acids. For example, hydrogen forms hydrochloric acid (HCl) with chlorine, sulfur forms sulfuric acid (H₂SO₄), and nitrogen forms nitric acid (HNO₃). These acids are critical in various industrial and chemical processes. Nonmetals such as carbon, nitrogen, oxygen, phosphorus, and sulfur are essential for life. These elements form the backbone of organic molecules like DNA, proteins, and carbohydrates, highlighting their critical role in biology and medicine. Noble gases like neon, argon, and krypton are used in lighting and lasers due to their ability to emit light when electrified. This property is utilized in neon signs and laser technologies. Silicon and germanium, both metalloid nonmetals, are pivotal in the electronics industry. Their semiconducting properties make them essential for manufacturing integrated circuits and solar cells. Noble gases (e.g., helium, neon, argon) are often used to create inert atmospheres in welding and in protecting reactive elements during manufacturing processes. Their lack of reactivity makes them ideal for these purposes.

Varied

The varied uses of nonmetals exends to explosives, fertiizers, flame retardants and extinguishers, lubricants, cryogenics and refrigerants, and medicines and pharmaceuticals. Nonmetals such as nitrogen and oxygen are key components in explosives. Nitrogen, in particular, is found in compounds like ammonium nitrate (NH₄NO₃), which is widely used in explosives and fertilizers. Elements like nitrogen, phosphorus, and potassium are critical components of fertilizers, which are essential for modern agriculture. These nonmetals help replenish soil nutrients, promoting plant growth. Compounds of nonmetals like bromine and phosphorus are used as flame retardants. Halons (compounds containing bromine) are effective fire extinguishers due to their ability to disrupt the chemical reactions in flames. Graphite (a form of carbon) is used as a lubricant due to its layered structure, which allows layers to slide over one another easily, reducing friction. Nonmetals such as nitrogen and helium are used in cryogenics and as refrigerants due to their low boiling points and inert properties. Nonmetals such as iodine and fluorine are used in medicine. Iodine is crucial for thyroid health, while fluorine is added to dental products to prevent tooth decay.

Exotic

Nonmetals have some exotic uses including as high-performance materials, nanotechnology, and smart technology. Xenon is used in specialized lighting and anesthetics due to its unique properties. Krypton is utilized in high-performance light bulbs and lasers. Boron and silicon are used to create high-strength materials. Boron fibers are used in advanced aerospace materials, while silicon carbide is used for cutting tools and abrasives. Carbon, in the form of graphene and carbon nanotubes, is used in nanotechnology applications for its extraordinary strength and electrical properties. Germanium and selenium are used in photovoltaic cells and infrared optics, making them crucial for developing smart technology and renewable energy sources.

Surprisingly common

Nonmetals are found in many everyday items or locations:

H	in water	O	detergents[b]	S	fertilizer	Br	bromide[c]	Xe	TVs[d]
He	party balloons	F	toothpaste	Cl	bleach	Kr	lamps	Rn	basements[e]
B	detergents	Ne	lighting	Ar	windows[f]	Sb	battery
C	pencils	Si	glassware	Ge	cameras[g]	Te	ceramics
N	beer widgets	P	matches	Se	glass[h]	I	antiseptic

Table

Density (D) and electronegativity (EN) in the periodic table

H

He

Li

Be

B

C

N

O

F

Ne

Na

Mg

Al

Si

P

S

Cl

Ar

K

Ca

Sc

Ti

V

Cr

Mn

Fe

Co

Ni

Cu

Zn

Ga

Ge

As

Se

Br

Kr

Rb

Sr

Y

Zr

Nb

Mo

Tc

Ru

Rh

Pd

Ag

Cd

In

Sn

Sb

Te

I

Xe

Cs

Ba

Lu

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

Rn

Ra

La

Ce

Pr

Nd

Pm

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Ac

Th

Pa

U

Np

Pu

Am

Cm

Bk

Cf

Es

EN: < 1.9 ≥ 1.9 (revised Pauling) Density:  < 7 g/cm3  D < 7 and EN ≥ 1.9 for all nonmetallic elements ≥ 7 g/cm3  D ≥ 7 or EN < 1.9 (or both) for all metals

f1 f2 f3  f4  f5  f6  f7 
Ce Pr Nd  Pm  Sm  Eu  Gd 

f8 f9 f10 f11 f12 f13 f14
Tb Dy Ho  Er  Tm  Yb  Lu