Question

The correct ground state electronic configuration of sodium is:

• A. 1 2 2 3
• B. 1 2 2 3
• C. 1 2 2 3
• D. 1 2 2 3

Answer 1

The correct option is C

1 2 2 3

The order in which the orbitals are filled is as follows:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s
We know that the maximum number of electrons in s, p, d and f subshells are 2, 6, 10 and 14 respectively.
Atomic number of sodium (Na) = 11
Therefore [Na] = 1$s^2$ 2$s^2$ 2$p^6$ 3$s^1$