Learning Lesson: Its a Gas, Man


OBJECTIVE Discover if carbon dioxide has an effect on temperature.
OVERVIEW The demonstration will show that excess carbon dioxide leads to higher temperatures.
TOTAL TIME 1 hour
SUPPLIES Two (2) clear 2-liter bottles
Two thermometers
Molding clay
Two seltzer tablets
Table top lamp used as a source of heat
PRINTED/AV MATERIAL None
TEACHER PREPARATION None
SAFETY FOCUS Summer safety rules


Background

Carbon dioxide has increased greatly in the atmosphere over the past 100 years. Although it comprises only 0.03% of the atmosphere, it has been linked to global warming.

Procedure
  1. Partially fill both bottles with water.

  2. Add the seltzer tablets to one of the bottles.

  3. Suspend the thermometers inside the bottles in such a way that you can measure the temperature of the air and seal the tops with molding clay.

  4. Place the lamp at equal distance between each bottle.

  5. After an hour, measure the temperature of the water in each bottle.
Discussion

The seltzer tablets supplied one bottle with a source of carbon dioxide. The "fiz" will have heated faster and to a higher temperature than in the other bottle. The increase in heating ability is due to carbon dioxide's high capacity to hold heat.

Fast Facts
To see the full effect of a greenhouse effect, look to the planet Venus. The atmosphere of Venus consists of 96% carbon dioxide, 3.5% nitrogen, with the remaining amount, less than 1%, of other gasses.

The carbon dioxide atmosphere has allowed the temperature of the surface to exceed 900°F (482°C). This is hot enough to melt lead. Space craft that have successfully landed on Venus, despite being well protected, have lasted only about an hour in the excessive heat and crushing pressure.


Live Weatherwise

Summer Safety Rules
Help reduce additional heat to the atmosphere by following the following conservation measures:

  • Protect windows. Hang shades, draperies, awnings, or louvers on windows that receive morning or afternoon sun. Outdoor awnings or louvers can reduce the heat entering the house by as much as 80%.
  • Conserve electricity. During periods of extreme heat, people tend to use a lot more power for air conditioning, which can lead to a power shortage or outage. Vacuum air conditioner filters weekly during periods of high use.
  • Keep lights turned down or turned off.
  • Avoid using the oven.

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