Chapter Three

10. Answer: a. CFCs coming from aerosols and other industrial processes have more than 10,000 times the heat-trapping properties of carbon dioxide, but the concentration is low enough that its overall effect is less than most other greenhouse gases.

CHAPTER THREE

1. Answer: b. For the most part, you are measuring both the kinetic energy of the molecules of gas in the atmosphere as well as the density of those molecules.

2. Answer: c. The difference in the width of a degree in Celsius and a degree in Fahrenheit is 1 to 1.8 so every degree Celsius equals 1.8 degrees Fahrenheit.

3. Answer: b. The best local thermometer is one not near a building or in your car but instead one in the shade about 5 feet from the ground.

4. Answer: c. Thermometers used to measure the official air temperature in the

US are about 5 to 6 feet off the ground in order to avoid any radiating heat from the ground surface.

5. Answer: c. The bimetallic strip thermometer is made with a strip that has two metals. The metals will expand differently to temperature, which can be calibrated to determine the actual temperature.

6. Answer: d. These thermometers are expensive and difficult to use but they are not at all sensitive to exposure to the sun's radiation.

7. Answer: b. Heated probes are used in aircraft in order to prevent buildup of supercooled water vapor on the device. They are slower than other probes, however, because calibrations to account for the heat coming from the device must be made.

8. Answer: a. Because the sun's rays strike the earth and heat this part only, your highest temperature will be within 1 to 3 centimeters from the earth's surface during the daytime hours.