Question

what do you mean valence and variable valency ​

Answer 1

Hey There.....!!

The number of electrons that an atom of an element loses, shares or gains is called the valency of that element.

For example,

Sodium has valency +1 since it loses one electron to attain octet

Certain elements have more than one valency and thus are known to show variable valency.

For example,

Iron has two valencies=>

+2 & -2

Hope this helps!!!

Answer 2

the no. of electrons present in outer most she'll is known as valence electrons.