Explanation:
Metals are the substances that contain excess of electrons.
For example, sodium is a metals that has atomic number 11 and its electronic configuration is 2, 8, 1. It has one extra electron in its valence shell and in order to attain stability it loses it valence electron readily.
Whereas non-metals are the substances that contain less number of electrons as compared to metals.
For example, chlorine is a non-metal that has atomic number 17 and its electronic configuration is 2, 8, 7. It needs one more electron to completely fill its valence shell.
On the other hand, noble gases are the gases that contain completely filled shells. Hence, they neither need to gain or lose an electron in order to gain stability. They are stable themselves.
Thus, we can conclude that metals is the family that generally has the valence electrons which are the easiest to remove from the atom.
