Nonmetal

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

A periodic table extract highlighting nonmetals
alt=A 10x7 grid, headlined "Nonmetals in their periodic table context". ¶ The 10 columns are labeled as groups "1", "2", "3–11", and then "12" to "18". The 7 rows are left unlabeled. ¶ Most cells represent one chemical element and are labeled with its 1 or 2 letter symbol in a large font above its name. Cells in column 3 (labeled "3–11") represent a series of elements and are labeled with the first and last element's symbol. ¶ Row 1 has cells in the first and last columns, with an empty gap between. Rows 2 and 3 each have 8 cells, with a gap between the first 2 and last 6 columns. Rows 4–7 have cells in all 10 columns. ¶ 17 tan-colored cells are mostly in the top right corner: both cells row 1 and the rightmost 5/4/3/2/1 cells in rows 2–6. ¶ 6 gray-colored cells are in a falling diagonal just left of the tan cells: 1/1/2/2 cells in rows 2–5. ¶ The remaining cells have light gray letters on a white background. Most have no border, but 4 have a dashed border, one in row 6 and 3 scattered in row 7.
  always/usually considered nonmetals[1][2][3]
  metalloids, sometimes considered nonmetals[a]
  status as nonmetal or metal unconfirmed[5]
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In the context of the periodic table 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 or usually attract electrons in a chemical bond with another element, and their oxides tend to be acidic.

Seventeen elements are widely recognized as nonmetals. Additionally, some or all of six borderline elements (metalloids) are sometimes counted as nonmetals.

The two lightest nonmetals, hydrogen and helium, together make up about 98% of the mass of the observable universe. Five nonmetallic elements—hydrogen, carbon, nitrogen, oxygen, and silicon—make up the bulk of Earth's atmosphere, biosphere, crust and oceans.

Industrial uses of nonmetals include in electronics, energy storage, agriculture, and chemical production.

Most nonmetallic elements were identified in the 18th and 19th centuries. While a distinction between metals and other minerals had existed since antiquity, a basic classification of chemical elements as metallic or nonmetallic emerged only in the late 18th century. Since then about twenty properties have been suggested as criteria for distinguishing nonmetals from metals.

  1. ^ Cite error: The named reference Larrañaga was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Steudel was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Vernon2013 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Goodrich etc was invoked but never defined (see the help page).
  5. ^ At: Restrepo et al. 2006, p. 411; Thornton & Burdette 2010, p. 86; Hermann, Hoffmann & Ashcroft 2013, pp. 11604‒1‒11604‒5; Cn: Mewes et al. 2019; Fl: Florez et al. 2022; Og: Smits et al. 2020


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