Question

Which one of the following is a correct electronic configuration of sodium?
(a) 2,8
(b) 8,2,1
(c) 2,1,8
(d) 2,8,1.​

Answer 1

d is the correct configuration for the sodium element which is 2,8,1.....hope it helps...

Answer 2

$\huge\texttt{ANSWER:-}}$

(d) 2, 8, 1.

Option (a): Atomic number of sodium is 11. Hence its atomic configuration also must have 11 electrons but 2,8 has only 10 electrons hence this option is incorrect.

Option (b): K shell can have maximum of 2 electrons but in this option K shell has 8 electrons .Hence it is incorrect.

Option (c): L shell can have maximum of 8 electrons and it needs to be filled first before filling M shell but in this option L shell has only 1 electron and M shell is filled before filling L shell. Hence this option is incorrect.

Option (d): since the atomic number of sodium is 11 and K, L, M shells can have maximum 2, 8, 18 electrons respectively. Therefore the correct electronic configuration of sodium is 2, 8, 1 where K shell has 2 electron, L shell has 8 electrons, M shell has 18 electrons. Therefore this option is correct.