Why the ocean have salty?

Ocean salt primarily comes from rocks on land. Some areas of the ocean are saltier than others. The concentration of salt in seawater (salinity) is about 35 parts per thousand, on average. Stated in another way, about 3.5 percent of the weight of seawater comes from the dissolved salts. 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. You may know that the oceans cover about 70 percent of the Earth's surface, and that about 97 percent of all water on and in the Earth is saline there's a lot of salty water on our planet. By some estimates, if the salt in the ocean could be removed and spread evenly over the Earth's land surface it would form a layer more than 500 feet (166 meters) thick, about the height of a 40-story office building. But, where did all this salt come from?. The answer is really very simple. Salt in the ocean comes from rocks on land.