Nonmetal 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 non-metal. (A few elements with intermediate properties are referred to as
metalloids.)
The elements generally regarded as nonmetals are
There is no rigorous definition for the term "nonmetal" - it covers a general spectrum of behaviour. Common properties considered characteristic of a nonmetal include
Only eighteen elements in the periodic table are generally considered nonmetals, compared to over eighty metals, but nonmetals make up most of the crust, atmosphere and oceans of the earth. Bulk tissues of living organisms are composed almost entirely of nonmetals. Most nonmetals form monatomic or diatomic molecules in their elemental state, unlike metals which (in their elemental state) do not form molecules at all.
