Question

if an atom has 8 electrons then which of the following correctly represents the electronic arrangement of the atom​

Answer 1

Explanation:

Atomic number of Mg is 12. So, according to Bohr's formula of distribution of electrons (2n2), K shell (n=1) can accommodate 2 electrons, L shell (n=2) can accommodate 8 electrons and the rest 2 electrons are accommodate in M shell. So its electronic configuration is 2,8,2.