Question

Sodium ion has a unit positive charge but sodium atom has:

• A. no charge
• B. + 2 charge
• C. + 1 charge
• D. + 3 charge

Answer 1

The correct option is A no charge

{a}. Sodium ion has a unit positive charge but sodium atom has no charge.

A sodium atom has 1 electron in its outer shell. It is in group 1 of the periodic table. When sodium reacts with non-metals (for example chlorine) it will lose its outer electron. Its outer shell will then have no electrons. It is as though the outer shell has vanished. The next shell in is full. This full inner shell becomes the new full outer shell. The sodium atom loses its outer electron to become a sodium ion.

The sodium ion still has 11 protons (11 positive charges) but now only 10 electrons (10 negative charges). The sodium ion has an extra positive charge, shown by the + sign. All group 1 metals will form a 1+ ion when they react with non-metals.