Question

What is the relationship between the number of Valence Electrons and valency?

Answer 1

The valency of an element and its valence electrons are same.             The valency of an element is given by the no. Of  electrons in its valence shell (valence electrons)    Hope you got satisfactory answer!!

Answer 2

The number of valance electrons is the total number of electrons in the outermost orbit.
The valency of an element depends on the number of electrons in the outermost orbit.
For example the no electrons in carbon is 6 .
It's valence electrons is 4 and it's valance is 4.
Whereas in oxygen the valency electrons is 6 and valency is 2.
Hope it helps.