INVESTIGATING AIR – HOT AND COLD

PROBLEM: Does hot air take up more space than cold air?

RESEARCH: Look up heat in a science textbook. Find out what causes something to become hot.

HYPOTHESIS: Based on your research where do you think the balloon will be biggest, from the room, the refrigerator, or the freezer?

MATERIALS:

four balloons

hot water

refrigerator/freezer

ice water

large bowl

glass bottle with narrow neck          

PROCEDURE:

1. Use a marker to write a number on each of the balloons: 1, 2, 3, and 4.

2. Blow up all three balloons. Tie them shut.

3. Using a tape measure, find the circumference of each balloon. Write the sizes in your notes.

4. Place balloon 1 outside the refrigerator, balloon 2 inside the freezer, and balloon 3 on the lower shelf of the refrigerator. Shut the doors and wait thirty minutes.

5. Quickly, before the balloons heat up outside the refrigerator, measure the balloons again. Record the measurements.

6. Fit balloon 4 over the mouth of the bottle.

7. Stand the bottle in the bowl and fill the bowl with hot water. Let the bottle stand for one minute. Describe what happened to the balloon.

8. Repeat step 7 using ice water.

DATA: Make a data table to record your observations and inferences.

CONCLUSION: This is not optional. You must explain what you learned by doing this activity.

Remember that you must answer the question you asked in your original problem statement.

NOTE: BE SURE TO HAVE YOUR PARENT OR GUARDIAN SIGNS YOUR WORK. PARENTS: YOUR SIGNATURE SHOWS YOUR STUDENT HAS DONE THE WORK.

TEACHER SECTION:

POSSIBLE HYPOTHESIS: Nothing will happen to the balloons. OR The balloons will inflate. OR The balloons will deflate.

POSSIBLE CONCLUSION: When the air is warmed, it expands and needs more space. When it is cooled it contracts and needs less space. The balloon in the freezer will contract the most, then the one in the refrigerator. The one in the room should not change. The air in the balloon with the bottle will expand in hot water and contract in the ice water.

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Judy Schneider

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