Verified Answer :

When a sodium atom loses an electron in its outer energy shell, or its valence shell it becomes a positively charged ion, a sodium cation with a charge of +1. It gives up the electron and undergoes potential bonding in order to acquire stability and or an octet of 8 electrons in its electron shell.

Answer : When a sodium atom loses an electrons in its outer energy then it will form a cation.

Explanation :

The sodium is metal that belongs to group 1 with atomic number 11.

The electronic configuration of sodium is, \(1s^22s^22p^63s^1\)

As we know that sodium atom loses an electron easily to acquire the stability.

The electronic configuration of sodium ion is, \(1s^22s^22p^6\)

According to the question, when a sodium atom loses an electron in its outer energy shell or valence shell then it becomes a cation which is a positively charged ion. That means sodium cation \((Na^+)\) having charge (+1).

Hence, when a sodium atom loses an electrons in its outer energy then it will form a cation.