If you have two glasses, one full of water and one half full of water, and you add the same amount of salt to each of them, which will be saltier?

1. If you have two glasses, one full of water and one half full of water, and you add the same amount of salt to each of them, which will be saltier? Why? Which will be denser? Why?

2. If you have two glasses, one full of red hot water and one full of blue cold water, which one is denser? What would happen if you combined them? Why?

3. Which has a higher heat capacity, a kilogram of water or a kilogram of sand? If you heated both of them at the same temperature for the same amount of time, which would be warmer? If you take the heat source away, which will cool more quickly? Why?