The ocean is salty because it contains dissolved salts, such as magnesium, calcium, and potassium, which give it its characteristic taste. These dissolved salts come from a variety of sources, including the erosion of rocks on land and the discharge of minerals from rivers.

The process of making the ocean salty begins when water from the oceans, lakes, and rivers evaporates, leaving behind the dissolved salts. As the water vapor rises into the atmosphere, it cools and condenses, forming clouds. When the clouds release their moisture as precipitation, the water flows back into the oceans, lakes, and rivers, carrying with it the dissolved minerals.

Over time, this process leads to a build-up of dissolved salts in the oceans, making them saltier. The salt content of the ocean varies depending on the location, with the highest concentrations found in the polar regions and the lowest concentrations found in the tropics. The average salt content of the ocean is about 3.5%, which is about 35 grams of salt per liter of seawater.