Julie Franzak

ELED 305-42

5/31/2007

Science Area: Earth Science

Concept: Expansion by heat

Students will probably assume that the water level will not change probably because they will not make the connection between the lit candles and the amount of trapped air under each of the glasses.

1. Attach one candle under cup A.

2. Attach two candles under cup B.

3. Attach three candles under cup C.

-if using a flat tray: attach the candles at different spots of it.

4. Fill each saucer with at leas 3/4cup of water.

5. Light all six candles

-wait till they all burn evenly

6. Place the cups at the same time over the candles on the saucer.

(have a student help)

1. Under which cup did the water level rise the highest?

2. Why were identical cups, saucers and candles used?

3. Do all the saucers need the same amount of water?

4. What variable was manipulated or changed in cups A, B and C?

5. Above which saucer was there the most heat?

6. Was the amount of air under each of the cups the same?

7. Why did the water level in cup C rise the highest?

Three variables in this activity did not influence the rising of the water because the same saucers, cups and candles were identical. The variable that was changed was the number of candles on each saucer causing the amount of heat under each cup to also be a variable. The number of candles on each saucer was the contributing factor that caused the air under the cup to expand momentarily before it hit the water; this is the reason why cup C trapped the least amount of air and exerted the lowest amount of pressure and also the reason why the water level raised the highest. Contrary to what people may believe, cup C did not burn more oxygen than cup A and cup B; the burning process in all the cups helped decrease pressure, however, the amount of oxygen was the same for them all.

Liem, Tik L. Invitations to Science Inquire. Chino Hills, CA: Science Inquiry Enterprises, 1987. 37.