Homework 7/22

Page 344 #1-4

1. Human exposure to ultraviolet radiation is more harmful than infrared radiation because while infrared is simply heat energy, ultraviolet is a more energetic form of sun radiation. Ultraviolet radiation can cause sunburns and skin cancer, harming many organisms with its ability to break covalent bonds.

2. Two essential roles played by visible solar radiation are that it energizes electrons in some chemical bonds. This supplies energy needed for photosynthesis reactions and the scattering of light in a sunset.

3. Since there is less water vapor, there is less greenhouse gas caused by water vapor in dry and arid regions. Infrared radiation is not as stored and reradiated and reflected back into the atmosphere from the entering of UV and visible light that is transformed into IR radiation in clouds, but the visible and UV radiation directly exposed to the surface of the earth is used to heat earth.

4. A) The daytime temperatures would be cooler, because with less greenhouse gases such as CO2 and H2O, less infrared radiation would be stored and reradiated and reflected back into the atmosphere from the transformation of UV and visible radiation to IR radiation in clouds Less stored heat energy would enter throughout the day.

B) Without stored heat energy in the atmosphere, nights would be very cold without the presence of the sun.

Page 350 #1-6

1. The mass of carbon dioxide produced daily by all 10 Riverwood High School buses is 1 kg.

2. 0.40 L of fuel are consumed daily by buses idling at Riverwood High School.

3. In a 180-day school year, 180 kg of carbon dioxide would be released into the atmosphere by these buses while idling. 72 L of fuel would be consumed.

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