Question

The valencies of oxide ion and nitride ion are ____ and ____ respectively.

• A. 2, 3
• B. -2, -3
• C. 3, 2
• D. -3, -2

Answer 1

The correct option is A 2, 3

Oxide ion, $O^{2-}$ has -2 charge on it, so its valency is 2.
Similarly, nitride ion, $N^{3-}$ has -3 charge on it, so its valency is 3.

Hence, the correct option is (a).