Question

If z=3 what would be valence of element

Answer 1

if z=3 then atomic no=3 
then electrons present is also 3 then 
k shell will have 2 electrons n l shell will have 1 electron
so the valancy = 1 

Answer 2

Atomic Number , Z = 3
No: of protons is the same as the atomic no:
No: of protons = 3
No: of electrons = 3

Electronic configuration = 2 , 1

Valency is the combing capacity of an element.
The combining capacity of this element is 1.

The element is Lithium.
It is metallic in nature.