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User:Sandbh/List of nonmetal meanings

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

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.[2]

Meanings

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Chemical elements that are nonmetals

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Main article: Nonmetal

In chemistry, a nonmetal is a chemical element that mostly lacks distinctive metallic properties. They range from colorless gases like hydrogen to shiny crystals like iodine. Physically, they are usually lighter (less dense) than elements that form metals and are often poor conductors of heat and electricity. Chemically, nonmetals have relatively high electronegativity (meaning they usually attract electrons in a chemical bond with another element), and their oxides tend to be acidic.

Semiconductors or insulators

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Main articles: Semiconductor and Insulator (electricity)

A nonmetal is a semiconductor such as selenium or lead telluride (PbTe),[3] or an insulator such as nitrogen or copper(I) chloride (CuCl).[4][5]

A semiconductor is a material that has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass, hydrogen or carbon dioxide.[4] An insulator is a substance that is a poor conductor of heat and electricity.[6]

"Over a period of more than half a century, Prof. Sir Nevill Mott pioneered the development of key concepts, models and theories for discussing the fundamental problem of metals versus non-metals (insulators and semiconductors)."[7][a]

A material in which electrical conductivity tends to zero at T = 0

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Main article: Absolute zero

Whereas metals are materials and substances in which the conductivity tends to a finite value for absolute zero (or infinite in the case of a superconductor),[9] the term "nonmetal" describes those for which the conductivity tends to zero for absolute zero.[7] At such low temperatures all substances are either solid or liquid, most notably in the case of liquid helium, which only solidifies under pressure.

In astronomy, the elements hydrogen and helium

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Main article: Metallicity

The astrophysicst Carlos Jaschek, and the stellar astronomer and spectroscopist Mercedes Jaschek, in their book The Classification of Stars, observed that:[10]

"Metals: (a term which is used very equivocally). 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. It is important to make sure in each particular case what the author really meant."

Nonmetallic materials

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Main article: 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.

While there are many mentions of “non-metallic materials” in the literature, it is the aims and scope statement for Nature Materials that clarifies that gases,[b] by their omission, are generally not counted as "materials":[11]

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.

Notes

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  1. ^ However, the term "insulator" can be used to include semiconducting materials[8]
  2. ^ e.g. H, He, CO2, SF6

References

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  1. ^ Woodhead, JA (2001). Earth Science. Vol. 3. Pasadena: Salem Press. p. 1742. ISBN 978-0-89356-003-4.
  2. ^ Chandler, H (1998). Metallurgy for the Non-metallurgist. Materials Park, OH: ASM International. p. 154. ISBN 978-0-87170-652-2.
  3. ^ Berger, LI (1997). Semiconductor Materials. Boca Raton: CRC Press. p. 86. ISBN 978-0-8493-8912-2. Se; Alligaier, RS (1985). "Metal-semiconductor transitions in doped IV-VI semiconductors". In Fritzche, H (ed.). Localization and Metal-Insulator Transitions. New York: Plenum Press. pp. 25–38(25). ISBN 978-1-4612-9521-1. PbTe
  4. ^ a b Gill, P (2016). Electrical Power Equipment Maintenance and Testing (2 ed.). Boca Raton: CRC Press. p. 231. Other insulating gases are SF6, nitrogen and fluorocarbons (freons).
  5. ^ Slichter, CP (1998). "The golden anniversary of nuclear magnetic resonance NMR: Fifty years of surprises". Proceedings of the American Philosophical Society. 142 (4): 533–556(537).
  6. ^ Daintith, J, ed. (2009). Oxford Dictionary of Physics (6 ed.). Oxford: Oxford University Press. p. 251. ISBN 978-0-19-923399-1.
  7. ^ a b Edwards, PP; Lodge, MTJ; Hensel, F; Redmer, R (2010). "'… a metal conducts and a non-metal doesn't'". Philsophical Transactions of the Royal Society A. 368 (1914). doi:10.1098/rsta.2009.0282.
  8. ^ Sgiarovello, C; Peressi, M; Resta, R (2001). "Electron localization in the insulating state: Application to crystalline semiconductors". Physical Review B. 64 (11): 15202-1 to 115202-10 (115202-1). doi:10.1103/PhysRevB.64.115202.
  9. ^ Hensel, F; Edwards, PP (1996). "Hydrogen—The first metallic element". Science. 271 (5256): 1692. doi:10.1126/science.271.5256.1692.
  10. ^ Jaschek, C; Jascheck, M (1990). The Classification of Stars. Cambridge: Cambridge University Press. p. 22. ISBN 978-0-521-26773-1.
  11. ^ "Aims & Scope". Nature Materials. Retrieved Jul 11, 2024.
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