why are rivers + lakes fresh water and oceans and sea salt? explain why fresh water from rivers turns to salt.

Question

testing your knowledge and education, 10 points to best explanation

Answer 1

Fresh water actually contains small amounts of dissolved salt. This salt is picked up fomr the land, when rain falls, saturates the ground, and runs off with dissolved minerals into streams. These streams ultimately end up flowing into the oceans. The heat from the sun drives weather systems that pick up (evaporate) distilled (salt-free) water vapor from the ocean, leaving the seas slightly more salty with each cycle. That vapor condenses over the land as rain, which washes even more salt into the rivers, and thence, the oceans.
After billions of years, the oceans have become very salty, and continue to become even more salty.

Answer 2

Without doing a chicken or the egg routine, the seas are salty because they have become a sink for salt from the rivers and lakes. Fresh water is NOT entirely free of salt, and when it flow to the ocean, the salt accumulates in the ocean. For instance, rivers may have 200 ppm of dissolved salts vs 35000 ppm in the ocean and seas. The balance of input of water from the rivers and the evaporation from the oceans and seas maintains the salt level in seas and oceans.