Question

four elements p q r s have atomic number 12 13 14 and 15 respectively what is the valence of q

Answer 1

atomic number of q=13
electronic configuration of q=2,,8,3
valency =3+.

Answer 2

K. L. M.

q(13). 2. 8. 3.

Valence electrons are the no. of electrons present in the outermost shell of an atom.