| 单词 | nonmetal |
| 释义 | nonmetal An element that is not a metal. Nonmetals can either be insulators or semiconductors. At low temperatures nonmetals are poor conductors of both electricity and heat as few free electrons move through the material. If the conduction band is near to the valence band (see energy bands) it is possible for nonmetals to conduct electricity at high temperatures but, in contrast to metals, the conductivity increases with increasing temperature. Nonmetals are electronegative elements, such as carbon, nitrogen, oxygen, phosphorus, sulphur, and the halogens. They form compounds that contain negative ions or covalent bonds. Their oxides are either neutral or acidic |
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物理辞典收录了3346条物理词条，基本涵盖了常用物理知识及物理英语单词词组的翻译及用法，是物理学习的有利工具。