Question

Explain the octet rule for the formation of –

Sodium chloride from a sodium atom and a chlorine atom.

Answer 1

Formation of sodium chloride NaCl, Na atom has atomic number 11 [2, 8, 1], There is 1 electron in the outermost M shell it is not possible to gain 7 electrons and to lose 1 electron is easier, by losing sodium atom because of \[\ce{Na+}\] ion.
While Cl atomic number 17 [2, 8, 7] has 7 electrons in outermost M shell for Cl atom it is easier to gain 1 electron, becomes \[\ce{Cl-}\] ion.
By losing 1 electron and by gaining 1 electron both sodium and chlorine attain octet configuration and become stable and there is the electrostatic force that pulls them and becomes sodium chloride.