Question

Sodium conducts electricity because:
(A) It is soluble in water
(B) It has only one electron in its outermost orbit
(C) It has mobile electrons
(D) It is an alkali metal

Answer 1

The electronic configuration of sodium is $1{s^2}2{s^2}2{p^6}3{s^1}$. If any metal can lose its valence electron easily, then it can conduct electricity as the electrons that are removed are delocalized through the material.

Complete step by step answer:
Let’s see how sodium in its metallic form is a good conductor of electricity.
- Sodium metal has a kind of a lattice arrangement in which the metal exists in positively charged atoms. They do this so because sodium has only one electron in its outermost orbital.
- The electronic configuration of sodium is $1{s^2}2{s^2}2{p^6}3{s^1}$. So, here sodium loses the electron of 3s orbital and becomes a positively charged ion.
- Therefore in this process, sodium atoms lose an electron each and these electrons are delocalized over the entire lattice. So, they are free to move.
- We know that if any metal possesses free electrons, then they are good conductors of electricity. They do so because the free electrons act as a carrier for the electric charge.
- Other alkali metals like Li, K also show this property because they also have similar electronic configuration like sodium.

Note: Note that any solid material that has free electrons is a good conductor of electricity. Remember that solid sodium chloride cannot conduct electricity because the electrons or the charged ions are not free to move, so electric charge is not transferred. However, aqueous solution of sodium chloride is a very good conduct of electricity because the charged ions are free to move in the solution.