Simply because salt dissolves in water. This salt was leached out of rocks by the water. It is not only salt that dissolves outstandingly well in water, but many other things as well.

Think about your daily breakfast. Heat water, hang a tea bag into it and the hot water will get taste. So components of the tea dissolve in water. The tea tastes sweeter, of course, if sugar is dissolved in it.

Since water is such a good solvent, there are many tasty soft drinks like Cola or Sprite.

Who hasn’t had fun by shaking a bottle of mineral water and spraying somebody with it? But where does the pressure in the bottle come from, where does the gas come from?

Now carbonic acid is dissolved in the mineral water. During the shaking, this carbonic acid splits into water and gas, namely carbon dioxide.

This explains how the gas got into the bottle of water, which you shook to get somebody wet.

The reason is that water possesses a high dielectric constant, which means that two electrically charged particles attract each other less intensely in water than in the air.

In the case of salt, these particles are the positive sodium ion and the negative chloride ion, which hold together when they are out in the air, forming crystals. In water, however, the ions dissociate, which means that they fall apart and the crystals dissolve.