module49REVIEW

541

In this module, we have seen that there is a natural process of ozone formation and ozone destruction in the stratosphere. As a result, with relatively constant ozone concentrations, harmful ultraviolet radiation is absorbed in the upper atmosphere and does not reach ground level where it could be harmful to plants and animals, including humans. However, the introduction of human-synthesized chlorofluorocarbons led to increased amounts of chlorine in the stratosphere, leading to destruction of stratospheric ozone. This caused an increase in UV-B radiation in certain locations on Earth. Since nations signed the Montreal Protocol on Substances That Deplete the Ozone Layer, stratospheric ozone depletion has begun to slow. In the next module we will turn from outdoor air pollution to indoor air pollution that occurs in houses and other living environments.

Module 49 AP® Review Questions

Question 1

1. The formation of ozone begins when an O2 molecule is split by

  1. UV-A radiation.

  2. UV-B radiation.

  3. UV-C radiation.

  4. UV-A or UV-B radiation.

  5. UV-B or UV-C radiation.

Question 2

2. How many ozone atoms can a single chlorine atom break down?

  1. 5,000

  2. 10,000

  3. 50,000

  4. 100,000

  5. 500,000

Question 3

3. Which is NOT a result of the reduction in stratospheric ozone?

  1. Reduced photosynthetic activity

  2. Increased skin cancer

  3. Increased eye problems

  4. Increased birth defects

  5. Suppressed immune systems

Question 4

4. Through international cooperation, the concentration of chlorine in the atmosphere

  1. has already decreased below 3 ppb.

  2. will stabilize around 3 ppb by 2030.

  3. has stabilized at 5 ppb.

  4. is expected to stabilize at 5 ppb by 2100.

  5. is expected to fall below 3 ppb by 2020.

Question 5

5. When is the Antarctic ozone hole largest?

  1. Early spring

  2. Late summer

  3. Mid-summer

  4. Late fall

  5. Early winter