How do molecules behave when heated?

How do molecules behave when heated? 

Materials needed

• Chalk or masking tape

Procedure

1. Have several students stand in a group.
2. Mark a border on the floor around the group with chalk or tape. Leave a few inches between the group and the border all the way around.
3. Ask students to move around slowly. Everyone should move constantly, but no one should move fast and there should be no pushing and shoving. They are to try to stay within the border marked on the floor.
4. Now instruct those in the group to move a bit faster. They are still to try to stay within the border.
5. Continue speeding up the movement of the group until they can no longer remain within the line marked on the floor.
6. Discuss what happened as those in the group increased their speed. Ask how this relates to the movement of molecules as temperature is increased.

What other type of energy accompanies light from the sun?

What other type of energy accompanies light from the sun?

 Materials needed

• Two magnifying glasses 
•  One sheet of paper 
• Glass bowl

Procedure

1. Ask your teacher where you should do this experiment. You will need to be in bright sunlight with no wind.
2. Put the paper in the bowl.
3. Hold the magnifying glass between the paper and the sun so a beam of light focuses on the paper.
4. Notice that as you move the magnifying glass closer to and farther from the paper, the point of light changes in size. Notice also that it gets brighter as it gets smaller.
5. Adjust the distance between the paper and the magnifying glass to make the point of light very small and bright. 

6. Pull the magnifying glass back about 1 cm (1/2 in). And watch the paper.
7. Do you see anything happening to the paper? If so what, and why do you think it is happening? What kind of energy is causing this to happen?
8. What do you might happen if you used two magnifying glasses focused on the same spot on the paper? Try it.