Question

why sea water is salty?​

Answer 1

Answer:

Salt in the sea, or ocean salinity, is mainly caused by rain washing mineral ions from the land into water. Carbon dioxide in the air dissolves into rainwater, making it slightly acidic. When rain falls, it weathers rocks, releasing mineral salts that separate into ions.

Answer 2

Answer:

Salt in the ocean comes from rocks on land. The rain that falls on the land contains some dissolved carbon dioxide from the surrounding air. This causes the rainwater to be slightly acidic due to carbonic acid.