Salt comes from rocks on land. Rainfall contains some dissolved carbon dioxide from the surrounding air. This causes it to be slightly acidic. As the rain erodes the rock, acids in the rainwater break down the rock. This process creates electrically charged atomic particles. These ions are carried through streams and rivers to the ocean. While many of these atomic particles get used by organisms in the ocean and are, therefore, removed from the water; some others are not used up. Chloride and sodium are the most common particles that get left behind and accumulate for long durations.
Why is there salt in the ocean?
