Question

Out of magnesium and Aluminium whose atomic size will be larger and why

Answer 1

Aluminium because it has more no of protons. In my opinion

Answer 2

there is nothing as atomic size,the Q might be who has the biggest atomic mass,or no. The ans is that since atomic no. of magnesium is 12 and atomic no. of aluminium is 13 the atomic mass of aluminium is greater greater which is 27.