Question

Which of the following configuration of electrons represent sodium?

• A. 2,8,4
• B. 2,8,5
• C. 2,3
• D. 2,8,1

Answer 1

The correct option is D

2,8,1

The correct option is (D).

Explanation of correct option:

1. The atomic number (Z) of sodium is 11 and the mass number (A) is 23.
2. Sodium has 11 protons, 11 electrons, and 12 neutrons.
3. For Sodium Na (Z=11) the electronic configuration is written as 2,8,1.

Explanation of incorrect option:

Option (A): Silicon Si (Z=14) has the electronic configuration of 2,8,4.

Option (B): Phosphorous P (Z=15) has the electronic configuration of 2,8,5.

Option (C): Boron B (Z=5) has the electronic configuration of 2,3.

Thus, 2,8,1 configuration of electrons represents sodium.