nonmetal

nonmetal
/non met"l/, n. Chem.
1. an element not having the character of a metal, as carbon or nitrogen.
2. an element incapable of forming simple positive ions in solution.
[1865-70; NON- + METAL]

* * *

      substance that does not exhibit such characteristic properties of metals (metal) as hardness, mechanical adaptability, or the ability to conduct electricity. This classification is generally applied to the chemical elements carbon, nitrogen, phosphorus, oxygen, sulfur, selenium, fluorine, chlorine, bromine, iodine, and the noble-gas elements. These elements have few physical properties in common; most are gases, one (bromine) is liquid, and others are solids.

      The atoms of nonmetals generally are small and contain relatively large numbers of electrons in their outermost shells. In the noble-gas atoms, the electron shells are completely filled; thus, the elements are almost completely inert. The other nonmetals have nearly filled electron shells, requiring only a few additional electrons to assume the stable, noble-gas configuration. Therefore, in the presence of other atoms, these nonmetallic atoms have pronounced tendencies to attract electrons to themselves (high electronegativities). They form chemical compounds by attracting electrons away from other atoms of lower electronegativities or by sharing electrons with atoms of comparable electronegativities.

      Although there are only a few nonmetallic elements, they constitute a large portion of the Earth's crust and are essential for the growth and existence of living things.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Nonmetal — Nonmetal, or non metal, is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal. (A few… …   Wikipedia

  • Nonmetal — Non met al, n. (Chem.) Any one of the set of elements which, as contrasted with the metals, possess, produce, or receive, acid rather than basic properties; a metalloid; as, oxygen, sulphur, and chlorine are nonmetals. [1913 Webster] …   The Collaborative International Dictionary of English

  • nonmetal — [nänmet′ l] n. 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… …   English World dictionary

  • nonmetal — nemetalas statusas T sritis chemija apibrėžtis Cheminis elementas, kuriam būdingas didelis elektrinis neigiamumas, blogas elektrinis ir šiluminis laidumas. atitikmenys: angl. non metal; nonmetal rus. неметалл …   Chemijos terminų aiškinamasis žodynas

  • nonmetal — noun Date: circa 1864 a chemical element (as boron, carbon, or nitrogen) that lacks the characteristics of a metal …   New Collegiate Dictionary

  • nonmetal — noun an element, such as phosphorus or chlorine, that does not have the chemical or physical properties of a metal …   Wiktionary

  • nonmetal — non·met·al ( )nän met əl n a chemical element (as boron, carbon, or nitrogen) that lacks the characteristics of a metal and that is able to form anions, acidic oxides, acids, and stable compounds with hydrogen * * * non·met·al (non metґəl)… …   Medical dictionary

  • nonmetal — nÉ‘n metl / nÉ’n n. chemical element without metallic properties …   English contemporary dictionary

  • nonmetal — non·metal …   English syllables

  • nonmetal — non•met•al [[t]nɒnˈmɛt l[/t]] n. 1) chem. an element not having the character of a metal, as carbon or nitrogen 2) chem. an element incapable of forming simple positive ions in solution • Etymology: 1865–70 non me•tal′lic məˈtæl ɪk adj …   From formal English to slang

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”