This activity is appropriate for: pre-k - 3rd grade / 4 - 8 years Try this simple science experiment to find out what happens when salt and water mix. Start by dissolving some salt in a small, disposable cup of water. Did the salt disappear? Ask students where they think it went. Write their answers down. Leave the cup in a sunny place. Show students how to mark the water level on the side of the cup. Encourage them to mark the water at the same time each day. Why do they think the water level is going down? When all the water has evaporated, show students the salt that remains in the bottom of the cup. Explain that the salt never really disappeared; it mixed with the water. Explain that the water evaporated, or turned into gas form, when the sun heated it. Once all the water evaporated, the salt stayed behind—in its original crystal form!
