Why is there salt in the sea? Also, is sea salt all sodium chloride or a mixture of different salts?

Answer 1

Salt in the seas is probably the result of many thousands of years of extraction by rain. While sodium chloride may be the most prevalent salt of the seas, the oceans are a soupy mixture of many salts (potassium chloride, potassium nitrate, sodium phosphates, sodium bromide and iodide, potassium bromide and iodide, fluoride salts, calcium and magnesium salts, iron salts, cesium salts) just to name a few. Think of the earth as a tea bag, and think of the oceans as brewed tea.