Question

Give reason
Electro valency of magnesium is 2

Answer 1

the  electron configuration of magnesium is (2,8,2). as it has 2 electrons in its outermost shell. it will loose those 2 electrons and become electropositive.

thus the valency of magnesium is 2.

Answer 2

the atomic no. of mg is 12 and in the last M shell has 2 electrons