Question

Can someone explain valency?

Answer 1

Valency is the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with.
"carbon always has a valency of 4"

Answer 2

Hello mate,

The valency of an element is the number of hydrogen atoms that can combine with or replace (either directly or indirectly) one atom of the element.

Hope this helps you out!