Question

Which of the following is the correct electronic configuration of a Sodium atom?

• A. 2,8,2
• B. 2,5,2
• C. 2,8,1
• D. 2,2,2

Answer 1

The correct option is C

2,8,1

Sodium has atomic number 11 and mass number 23.

The nucleus of sodium has 11 protons and 12 neutrons and it is surrounded by 11 electrons.

The electronic configuration of sodium:

K shell or I shell= 2 electrons ($2\times 1^2$=2)

L shell or II shell= 8 electrons ($2\times 2^2$=8)

M shell or III shell= 1 electron (1 remaining electron)

Electronic configuration of sodium atom= 2, 8, 1