Question

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

Answer 1

Valency -The valency of an atom is the number of electrons that are required to be added or removed from the outermost shell of an atom to complete its octet

As per definition,

In the case of Atom (a) -

1. As shown in the figure, the outermost shell of Atom (a) is fully filled as its octet is complete.
2. Therefore, it has zero valencies, as it has $8$electrons in its valence shell, making the configuration stable.

In the case of Atom (b) - As shown in the diagram, the outermost shell of Atom (b) doesn't have a fully filled octet, it contains 7 electrons.

Therefore, the valency of atom(b) is$1$as it has $7$ electrons in its outermost shell. It can accept 1 electron to achieve octet configuration.

Hence, the valency of atom (a) is zero, and atom (b) is $1$