Question

22. Yuko designed an experiment to test the effect of heating and cooling on air. She blew up two

Balloons to similar sizes and measured their circumferences. She placed one balloon in a
freezer for one hour and left the second balloon on the table. After one hour she measured
their circumferences again. She then left both balloons on the table for one more hour. The
graph below shows the change in the sizes of the balloons during the experiment.
Circumference in
Centimeters
60
40
Effects of Heating and Cooling
on an Inflated Balloon
1
Time in Hours
2
Control Balloon
Test Balloon
Which statement BEST explains the differences seen between the two balloons during the
experiment?
A Air contracts when cooled but is not affected by warming.
B. Cooling causes air to contract and heating causes air to expand.
C. Balloons put more pressure on cold air than room temperature air.
D. Freezing causes balloons to contract and thawing causes them expand.

Answer 1

B. Cooling causes air to contract and heating causes air to expand.

The graph shows that the circumference of the test balloon decreases when placed in the freezer and increases when left on the table. This indicates that cooling causes the air inside the balloon to contract, resulting in a decrease in circumference. Conversely, when the balloon is left on the table, it returns to its original size, indicating that the air inside expands when heated.

Therefore, the statement that best explains the differences seen between the two balloons during the experiment is that cooling causes air to contract and heating causes air to expand (option B).