Question

What is covalency? And what is maximum covalency?

Answer 1

Dear Student,

Covalency of an element in a covalent compound is equal to its total numbers of electrons involved in covalent bonding or number of unpaired electrons available for covalent bonding. Eg. covalency of H in H₂ molecule is 1, covalency of H in H₂O is 1 while covalency of O is 2, etc.
Maximum covalency of an element is the maximum number of covalent bond that an element can form with its neighbouring atom. It is equal to ns+np electrons of the valence (nth) shell. N, O, F are exception due to non availability of vacant orbitals in their shell. Eg. covalency of Cl is PCl₃ is 3, but its maximum covalency is 7(2 3s electrons + 5 3p electrons ) .