Question

What is the source of most salt in the ocean?

Answer 1

Rocks and minerals on land.

Explanation:

Rainwater is very slightly acidic, due to the dissolution of carbon dioxide in it. The very dilute carbonic acid thereby formed has the effect of dissolving out minute quantities of ions (various metal and non metal ions depending on the composition of the rock).

Some ions are used up by marine organisms and thereby do not feature at a significant level. Others remain in the water. Sodium and chloride ions tend to be left in the water.