Element P with 6 electrons has an atomic number of 6 = 2, 4 → C Element Q with 11 electrons has an atomic number of 11 = 2, 8, 1 → Na Element R with 15 electrons has an atomic number of 15 = 2, 8, 5 → P Element S with 17 electrons has an atomic number of 17 = 2, 8, 7 → Cl Given the above is the electronic arrangement of P,Q,R,S elements, Q will form an electrovalent bond with S because element Q(metal) has a valence of electron of 1 it can donate to another element needing 1 electron, which is element S (a non-metal). Thus, electrovalent bond is formed in compounds where there is a transfer of electron from metals to non-metals.