What are the characteristics of metal atoms from the point of view of atomic structure?

At the external energy level, metal atoms have a small number of electrons (1-3) and they easily donate them in chemical reactions. Mostly these are elements of the I-II group of the periodic system.

The atoms in which the d- or f-sublevels of the previous energy level are filled with electrons also exhibit metallic properties (elements III – VIII b of groups of the periodic table, lanthanides and actinides).

Metals are also elements III – VIII and groups of the periodic system, located in the 5th – 7th period. Their outer electrons are far from the nucleus of the atom. These atoms are easier to donate electrons to the outer level than to attach, the metallic properties are enhanced.