Everyone who has been to the beach knows that seawater is salty. Everyone also knows that fresh water in rain, rivers, and even ice is not salty. Why are some of Earth's waters salty and others not? There are two clues that give us the answer. First, “fresh” water is not entirely free of dissolved salt. read more
Partly it is because the water tastes salty if it contains sodium ions and chloride ions. If the minerals associated with a lake don't contain much sodium, the water won't be very salty. Another reason lakes tend not to be salty is because water often leaves lakes to continue its trip toward the sea. read more
Everyone who has been to the beach knows that seawater is salty. Everyone also knows that fresh water in rain, rivers, and even ice is not salty. As rainwater passes through soil and percolates through rocks, it dissolves some of the minerals, a process called weathering. read more