Evaporation/Condensation

Over the last two days we did a neat science experiment to see what would happen to a damp paper towel overnight. On one side of the balance scale the paper towel was placed into an open cup with the top under the cup. On the other other side we put the top on the cup. 24 hours later, as you can see, the cup on the left with the top on it had a greater mass than the other side. In the cup on the left we found that the water condensed (water droplets were made) on the inside of the cup, and the cup on the left had no water in it and the paper towel was dry! It had evaporated (turned into a gas!)