4BSB pg.350 #1-4

1) Human exposure to ultraviolet radiation is more harmful than exposure to infrared radiation because infrared radiation is basically heat energy, while ultraviolet light  can cause sunburns, and with extensive exposure could lead to skin cancer. 

2)  Two roles played by visible solar radiation is that it can energize electrons in some chemical bonds and it can also scatter throughout Earth and causing red sunsets and blue skies. 

3)  Dry, arid regions experience wider air-temperature fluctuations from night to day than do states with more humid conditions because since there is less water vapor, infrared radiation is not stored, reradiated, and reflected back into the atmosphere from the transformation of UV and visivle radiation to infrared radiation in the clouds, resulting in the lack of heat stored in the clouds. 

4) 

a. The daytime temperatures would be much cooler because less stored heat energy would enter throughout the day.
b. Nights would be cold since there is less heat to store during the day.