-
Relate the changes in volume of gases to changes in the temperature.
-
Explain why the volume of a gas increases as the temperature increases.
-
Predict the volume of a gas when its temperature is specified.
Materials Needed: balloons, helium, freezer, heater
-
As a group, inflate two balloons with helium. Measure to see that they are the same size. Ask the students to predict (in writing) what they think will happen to each balloon.
- Place one balloon in a freezer. Place the other balloon in a very warm place (near the heater or outside on a very hot day).
-
Take the balloons out and measure to see if the prediction was accurate.
Materials Needed: balloons, helium, freezer, heater, plastic bottle, dry ice, cooler
- Partially fill a plastic two-liter bottle with hot water and cap it tightly.
- Immediately put the bottle in a cooler with dry ice and close the cooler lid.
-
Have the students predict in writing what they expect to happen.
-
After a few minutes, take the bottle out of the cooler. (The bottle should have collapsed due to the cooling of the gas inside and the slowed molecular movement.)
With a partner, write a paragraph addressing the following questions:
-
Why is the following warning placed on most spray cans: "DO NOT place in hot water or near radiators or stoves. DO NOT incinerate, even when empty. DO NOT store at temperatures above 120° F."
-
Why does a car's tire pressure increase during summer months?
-
Why do car or bicycle tires seem under-inflated in winter months?
This activity was written by Meghan O'Leary & Jaci Kottman.
Helium Balloons (Graphing)
Objective
Students will make a graph using data gathered in the balloon experiment.
Materials Needed
6 balloons for each group (same size balloons), helium, thermometers
Procedure
- Put students into groups of two or three.
- Students will blow up four balloons, making sure the circumference is the same on each balloon.
- The four balloons will each be placed in a different location, each at a different temperature, for 15 minutes. Put a thermometer with the balloon so that the temperature can be noted.
- The circumference will then be measured and graphed.
a. The graph will be a double line plot with temperature on the x axis and size on the y axis.
b. A line for the original circumference measurement should be displayed. A second line showing the circumference after changing the temperature should be drawn.
-
Follow the same procedure using helium as the inflating gas.
-
Using the same graph, display a third line in a different color that shows the circumference after changing the temperature.
-
Students will write an explanation telling what the graph shows them. They should use numbers in their explanation.
Evaluation
|
 |
Copyright©2001-2003, Northeastern Educational Television of Ohio, Inc. All rights reserved.
|
|