Question

The electrons which are not involved in
bonding are called valence electrons.​

Answer 1

The remaining six valence electrons of each chlorine atom are not involved in bonding and are concentrated around their respective atoms. These valence electrons, customarily shown as pairs of electrons, are variously called nonbonding electrons, lone pair electrons, or unshared electron pairs.

Answer 2

The valence electrons which are shared or which participate in the formation of covalent bonds are called bonding electrons. The pair of bonds which are not shared with another atom is called lone pair of electrons. They are also called non-bonding electrons or unshared pairs.