Lesson 2.2: Changing State—Evaporation
Heating and Evaporation
- Compare the number of motion lines and the spacing of the water molecules in the water on each paper towel. Heated water molecules have more energy and move faster than the room temperature water molecules. These faster moving molecules are able to overcome the attractions they have for other water molecules more easily and evaporate.
- The molecules in liquid water are attracted to one another but are able to slide past each other. If you look closely, you can see some molecules where the hydrogen atoms of one molecule are “bonded” to the oxygen of another.
Note: The water molecules are shown further apart than they would be so that molecules in the background can be seen.