Question

what is valence electron​

Answer 1

Answer:

In chemistry and physics, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair. 

Answer 2

the electrons which is present in last cell of an atom is called valence electron.

example,

sodium has a atomic no = 11

electronic configuration = 2 , 8 , 1

so the valence electrons of sodium is 1

Hope it's help ✌✌