seawater

Seawater is the salty water that makes up the oceans and seas, covering about 71% of Earth's surface. It contains about 3.5% dissolved salts, primarily sodium chloride (common table salt), along with other minerals like magnesium and calcium. These salts come from rocks and land carried to the ocean by rivers, as well as underwater volcanic activity. Seawater plays a crucial role in regulating Earth's climate, supporting marine life, and influencing weather patterns. Its saltiness varies depending on location and the balance of freshwater input and evaporation.