Find out the valency of the atoms represented by the Figure (a) and (b).

Explanation

(a) It has electronic configuration
`" "{:(K, L, M ),(2, 8, 8 ):}`
Its outer shell complete octet.
Hence, its valency = 0
(b) It has electronic configuration
`" "{:(K, L),(2, 7):}`
It can easily gain one electron to complete its outermost octet.
Hence, its valency = 1