Why is ocean water salty?
Show answer & explanation
Answer: Rivers carry minerals to sea
Salt from ancient sea creatures — Wrong. Ocean salt doesn't come from organisms. It accumulates from minerals dissolved by weathering of rocks on land and carried by rivers.
Seawater evaporates salt crystals — Wrong. Evaporation concentrates existing salt but doesn't create it. Salt comes from dissolved minerals washed from land into oceans over billions of years.
Rivers carry minerals to sea ✓ — Correct! Rain weathers rocks on land, dissolving minerals (sodium, chloride, magnesium, etc.). Rivers carry these dissolved minerals to the ocean. Water evaporates from oceans but minerals stay behind, accumulating over billions of years. That's why oceans are salty (~3.5%) but rivers are fresh!
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