Question

what is the group of 2,8,2 electron configuration

Answer 1

Electronic configuration of magnesium is 2,8,2
this reveal that the first shell of magnesium atom 2 electrons are present, similarly second shell contain 8 electrons and last shell has 2 valence electron

Answer 2

2,8,2 =Mg
no. of group = no. of electrons present on last s orbitals.

here 1s2 2s2 2p6 3s2