Question

when common salt is mixed in water why the level of water remain unchanged

Answer 1

Water is known as the universal solvent because it dissolves more substances than any other liquid. It can do this because water molecules carry an electric charge strong enough to disrupt the molecular bonds of the substances it dissolves. One such substance is sodium chloride (NaCl), or table salt. When you put salt in water, the sodium and chlorine ions separate and attach themselves to individual water molecules. The resulting solution becomes an electrolyte, which means it's capable of conducting electricity.

Answer 2

Heyaa......

The answer is Common salt when added to water,liquid have a few intermolecular spaces and the common salt settle in that.
But some time we can't add salt if it become more then it will settle Down it's because the saturation has a limit.

Hope it helped you dear