Differentiate between oxidation number and valency

Valence electrons:- The electrons that participate in forming chemical bonds & that lies in outermost shell. Example- carbon has six electrons. 2 in inner & 4 in outer shell. So, it has a valency of 4.

Oxidation Number:- It is know, how oxidized an atom is in a compound or molecule.

# Valency cannot be zero or negative, but oxidation number can be zero, negative or positive depending on state of matter