Question

write the number of valence electron of K and n

Answer 1

Here is the answer K_ pottasium
N_ nitrogen

K valency = 1
N valency = Hope helps

Answer 2

Valence electrons : No. of electrons present in the outermost shell of an atom.
Electronic configuration of :
Nitrogen(N) : 2,5
Potassium (K) : 2,8,8,1
No. of valence electrons in:
N : 5
K : 1