Homework Assignment 20

4SBS #1-8 p. 360, #14-20 p. 361

1. The frequency of electromagnetic radiation and energy are directly proportional. Wavelength of electromagnetic radiation and energy are inversely proportional.

2. The word spectrum is a good descriptor of the types of energy found in electromagnetic radiation because the spectrum shows the vast range of energy.

3. Visible light is useful in plant photosynthesis while other forms of electromagnetic radiation are not because visible radiation can supply energy needed for the reactions by energizing electrons in chemical bonds.

4.

• a. Infrared, visible, ultraviolet
• b. Infrared radiation affects living things because it is essentially heat energy, which provides warmth. Visible radiation affects living things through photosynthesis because it can energize electrons in chemical bonds. Although ultraviolet radiation can cause sunburns, skin cancer, and can kill bacteria and destroy viruses, it can affect living things in a positive way because some exposure fuels production of Vitamin D.

5. Ultraviolet light is effective for the use of sterilizing lab protective goggles because UV-C radiation can kill bacteria and destroy viruses, unlike visible light.

6. Infrared radiation is absorbed by carbon dioxide and water vapor, and the energy is then projected back to earth. The majority of visible radiation directed towards earth travels to Earth's surface on a clear day. UV-C radiation is absorbed in the stratosphere before reaching earth's surface and most UV-A and UV-B radiation is absorbed by the stratospheric ozone layer.

7. The more greenhouse gases produced, the more infrared radiation is absorbed. There is then more energy on earth’s surface, hotter water, and a much hotter planet.

8.

• a. Asphalt warms up more quickly when exposed to sunlight because right when solar radiation makes contact, it is reflected back into space. Lake water does reflect light, but also absorbs and stores heat.
• b. Water may act like greenhouse gases and absorb infrared light. Asphalts directly reflect light sources back into space.

14. Atmospheric CO2 and water vapor help maintain moderate temperatures on Earth's surface because CO2 blocks out the infrared light, sustaining the correct amounts of UV visible light entering Earth.

15.

• a. Natural processes: decay of plants/animals, absorption of CO2 -- Human activities: burning fossil fuels, bonfires
• b. Natural processes: plants decay, cows let out methane -- Human activities: bonfires, methane

16. 

• Temperature increase: methane and CO2 increase
• Temperature decrease: ozone increase and solar energy decrease

17. On a sunny winter day, a greenhouse with transparent glass walls is much warmer than is a structure with opaque wooden walls because the glass permits visible and UV light to enter the greenhouse but at the same time does not allow the reradiated infrared radiation leave the greenhouse.

18. 

• a. 

• b. 

19. Three chemical reservoirs of carbon atoms are limestone, fossil fuels, and plant decay.

20. Over time, a particular carbon atom can be part of the atmosphere, biosphere, lithosphere, and hydrosphere. A carbon atom from a decayed fish was in the ocean water, which was then used to water a plant. The carbon that makes up the plant can be released when it decays and then fossilized. It can after get pumped from the ground and used as petroleum gas. The gas may fuel cars and later pollute the atmosphere.