Why the sea is salty

You could be out in the middle of the ocean - surrounded by thousands of miles (kilometers) of water - and not have a drop of water you could drink. For seawater is full of salt. If you did drink it, it would simply make you more thirsty.

The sea is salty because rivers dump salt into it. All the rivers that flow down mountainsides and over the land tear loose tons and tons of minerals. Most of these minerals are different kinds of salts. The rivers carry these salts to the sea.

There's never enough salt in a river to make the river water taste salty. But rivers have been dumping salt into the sea for millions of years. By now, there is enough salt in the sea to cover all the land on earth with a layer of salt hundreds of feet (meters) deep !