Have students use bubbles to study air movements in other ways.
- Have them gently blow bubbles up into the air and observe where the bubbles travel. Ask, Do the bubbles eventually fill the room? and Do they move upward or downward?
- Differences in temperature cause air movement. Have students predict how variations in air temperature would affect the distribution of dust and other pollutants within a room or building.
- Have students look at a map or globe. Explain that the sun heats air near the equator more than it heats air near the poles (the poles receive less direct heat from the sun). Ask, How do you think these differences in temperature influence the movement of air on Earth? Then show students a chart of global wind patterns, such as the one on this slide, which shows prevailing wind circulation on Earth (indicated by the white arrows). Be sure to point out how wind patterns vary at different locations.
Blow up a Ziplock bag (1 gallon size) until it is fully inflated and the sides are tense. Do this by “unzipping” the bag slightly, blowing in, and closing it quickly without letting air out. Let the bag sit for 5-10 min. During this time, the air in the bag will cool from your body temperature (98.6 ºF) to room temperature (68-77ºF). This drop in temperature will cause the air in the bag to contract and exert less pressure on the sides of the bag. Thus, over time, students will notice that the sides of the bag become less taut.
For a more dramatic display of the contraction of air at cooler temperatures, blow up a second Ziplock bag and place it in the freezer for 5-10 min. Then compare this bag to the one at room temperature.
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Funded by the following grant(s)
The Environment as a Context for Opportunities in Schools
Grant Numbers: 5R25ES010698, R25ES06932
Foundations for the Future: Capitalizing on Technology to Promote Equity, Access and Quality in Elementary Science Education