Question

Describe how sodium and chlorine atoms are changed into ions when they react with each other to form sodium chloride, NaCl. What is the name given to this type of bonding? (At. No of sodium = 11; At. No. of chlorine = 17)

Answer 1

The electronic configuration of sodium is 2, 8, 1. The outermost shell contains one electron. For the atom to be stable, it should lose one electron and thus attain the noble gas configuration of 2, 8.

Na - e^- → Na⁺

The electronic configuration of the chlorine atom is 2, 8, 7. The outermost shell contains seven electrons. For the atom to be stable, it requires one electron and thus attain the noble gas configuration of 2, 8, 8.

Cl + e- →  Cl^-   

Hence sodium donates one electron to the chlorine atom when they react with each other to form a stable compound, sodium chloride, NaCl. This type of bonding that takes place through transfer of electrons is known as ionic bonding.