Question

Why is valency called combining capacity of an element?

Answer 1

Answer:

To attain stability, magnesium loses two valence electrons and completes its octet. In this way, it attains stability. So the combining capacity of an element is known as its valency.

Explanation:

Answer 2

Answer:

The valency of an element is the same as combining capacity.

Explanation:

To get stability some elements will combine with other elements and complete their octet. For example in the case of aluminum $3e$ is present in the valence shell that is its valency is 3. But to attain stability it loses $3e$ So its combining capacity is also 3. Hence we can say that valency is the same as combining capacity.