Elements with metal universality. There are more than 80 kinds of metal elements with similar properties, which mainly show reducibility, luster, good electrical and thermal conductivity, hardness and ductility, and are generally solid at room temperature (except mercury: mercury is a silvery white liquid at room temperature, commonly known as "mercury").

Except for a few metals such as Sn (Sn), Sb (Sb) and Bi (Bi), the outermost electrons of most metal atoms are less than 4, so their atoms tend to lose electrons and often exist in the form of cations. Their compounds and hydroxides are usually alkaline.

Arrangement of metal elements in the periodic table: [1]

The first main group (except H) is an alkali metal element, and the second main group is an alkaline earth metal element. The third to second groups are transition metals, which usually have high density, high melting point and good electrical conductivity, thermal conductivity, ductility and corrosion resistance. The compounds of transition metals and their solutions are mostly colored.

Atomic structure characteristics of metal elements;

Except for a few metals such as Sn, Sb and Bi, the outermost electron number of most metal atoms is greater than or equal to 4. The peripheral electron configuration of the main group metal atom is ns 1 or ns2 or ns2 np( 1-4), and the peripheral electron configuration of the transition metal can be expressed as (N- 1) D (65438). The atomic radius of main group metal elements is larger than that of nonmetallic elements (except rare gases) in the same period.