Question

10. Group IIA elements: Be, Mg, Ca, Sr have a ___________charge. +2 or +3

Answer 1

ANSWER : Group IIA elements : Be, Mg, Ca,Sr have a +2 charge.

In periodic table , Be, Mg, Ca,Sr, Ba, Ra these elements are placed in Group IIA. The E.C of these elements are

₄ Be : [He] 2s²

₁₂ Mg : [Ne] 3s²

₂₀ Ca : [Ar] 4s²

₃₈ Sr : [Kr] 5s²

₅₆ Ba : [Xe] 6s²

All these elements have two electrons in the valence shell. After loosing these two electrons elements acquire a noble gas electronic configuration and achieves extra stability. Hence , they have +2 charge.

If 3 electrons are lost by these elements, they do not acquire noble gas electronic configuration . Hence, they do not have +3 charge.