why ocean water is salty

The ocean water is salty because of the presence of dissolved salts in it. When water flows over rocks and soil, it dissolves small amounts of minerals and salts. This water then flows into rivers and eventually into the ocean, where the process of evaporation and precipitation takes place.
During evaporation, only pure water molecules turn into water vapor and leave behind the dissolved salts and minerals. As the water vapor rises and cools, it condenses into clouds, and the precipitation falls back onto the Earth's surface in the form of rain or snow.
However, the water that falls on land, like rivers and lakes, continues to flow back to the ocean, carrying with it more dissolved salts and minerals. Over time, the accumulation of these dissolved salts and minerals in the ocean leads to an increase in the salinity of the water.
The most abundant salt in the ocean is sodium chloride (table salt), followed by magnesium and calcium salts. The average salinity of the ocean is about 3.5%, which means that for every 1 liter of ocean water, there are 35 grams of dissolved salts.