Why is the Sea Salty?

Put two or three pinches of table salt into half a glass of water and stir the water with a spoon.
What happens?
The salt seems to disappear.
In fact, it is still there, but it has dissolved in the water.
The salt and water have formed a solution. Each grain of salt is a crystal. This is a group of particles arranged in a regular pattern. Water molecules break the crystals up into individual salt particles, which are too small to be seen. This is why the salt seems to disappear.

Most of the earth's surface is covered with a solution.
We call this solution sea water.
There are many things dissolved in it, but the most common substance is a chemical called sodium chloride.
We know it better as table salt.
It makes the sea taste salty.

You may think the salt has disappeared. But taste the water and you will find the salt is still there. You cannot see it because it has dissolved.
Some of our salt comes from the sea. First, sea water is allowed to flow into large shallow pools.
The heat of the sun evaporates the water, leaving the salt behind.
Substances which dissolve in water are described as soluble substances.
We can make soluble substances dissolve faster by stirring, shaking or warming them.

What would happen if you continued to put more salt into the water? 

After a time, no more would dissolve, however much you stirred it, shook it or warmed it. The solution would be saturated. A saturated solution cannot hold any more of a soluble substance.