Number of valency electrons present in Calcium,Ca is

Atomic number of calcium, Ca is Z =20.

Electronic configuration of Ca is$1{\text{s}}^{2}2{\text{s}}^{2}2{\text{p}}^{6}3{\text{s}}^{2}3{\text{p}}^{6}4{\text{s}}^2$ .

Valency shell of Ca ,$n=4$ ; No. of valence electrons in Ca is 2.