What is covalency?

Explanation

Covalency is explained by the number of covalent bonds an element can form with other atoms to get extra stability.

All we can say is that an element can share its electron to another element to get stable electron configurations.

If an atom shares one electron then its covalency is 1, if it shares two electrons then its covalency is 2.

Example  covalency of carbon is 4 because it shares  4 electrons to the other atom ( another carbon or hydrogen atom )  to fulfill its octet electronic configuration and get extra stability.

Final answer:

So, Covalency is the number of shared electrons to the other atom to get extra stability