The Unconditional Guru

Total valency of a compound is zero. Before starting the topic lets talk about valency.

Valency  is the combining capacity of an atom or element.

Now if the element is having a valency = 2,

It means it can make two bonds,

Now if two bonds are made,  will it have a capacity to join further?

No, it can’t make any bond. Thus the combining capacity of elements will be zero.