Question

mg+2 is smaller than O-2in size,though both have same electronic configuration ,why?

Answer 1

Yes, Mg²⁺ is ion smaller than that of O^2- because in Mg²⁺ 2 e-s are deducted from its shell where as in O^2- 2 e-s are adding in ti d shell as a result oxygens shells increase leading to in crease in size where magnesium decreases in size due to deduction of 2 electrons.