Question

The variable valency in transition elements occurs due to .............

(A) difference in the energies between the (n – 1) d and np electrons 

(B) similarity in the energies between the ns and np electrons 

(C) similarity in the energies between the ns and (n – 1) d electrons 

(D) difference in the energies between the ns and (n – 1) d electrons

Answer 1

Correct option: (C) similarity in the energies between the ns and (n – 1) d electrons