Which of the following correctly represent the electronic distribution in the atom?
(a) 3, 8, 1
(b) 2, 8, 2
(c) 1, 8, 3
(d) 8, 2, 2
Answer: B
Solution:
The electron configuration of an atom shows the number of electrons in each sublevel in each energy level of the ground-state atom. The first sublevel filled will be the sublevel, then the
sublevel, the
sublevel, the
and so on. Atomic number of magnesium is 12 and Electron configuration is
So, according to Bohr's formula of distribution of electrons
,K shell
can accommodate 2 electrons, L shell
can accommodate 8 electrons and the rest 2 electrons are accommodated in M shell. So, its electronic configuration is
.