Question

difference between valency n its n valence electron

Answer 1

The electron present in the outermost shell of an atom is called valence electron.

valency is the electron sharing , giving , taking ability of an atom which is decided by valence electron.

Answer 2

The combining capacity of an element is called as valency
Whereas the the number of electrons present in the outermost shell of an element is called as a valence electron
Hope this helps you