Ozone Practice 100%

Ozone located in the troposphere is _______. a. considered a pollutant b. beneficial to living organisms c. higher in concentration than ozone in the stratosphere d. all of the above

A. Considered a pollutant

Which of the following is not a health risk associated with a depleted ozone layer? a. respiratory illness b. skin cancer c. cataracts d. all of the above

A. Respiratory illness

Where is over 95% of incoming ultraviolet radiation absorbed? a. the stratosphere b. the mesosphere c. the troposphere d. the thermosphere

A. The stratosphere

The following is a chemical reaction for _______ with ozone. a. chlorofluorocarbons b. halons c. UV radiation d. none of the above

B. Halons

Compare the health and environmental risks associated with ground-level ozone to the health and environmental risks associated with ozone layer depletion.

Both ground-level ozone and depletion of the ozone layer cause environmental and health concerns. Ground-level ozone is a pollutant that is harmful to organisms when it is breathed in. Ozone in the troposphere can also cause an increase in surface temperatures. Depletion of ozone in the stratosphere causes health and environmental risks indirectly. Since ozone absorbs UV radiation, having less ozone in the stratosphere means more UV radiation will reach the troposphere. This causes greater risk of skin cancer and cataracts. Changes to global climate and harmful effects to plant life are also concerns.

What percentage of ozone is contained in the stratosphere? a. 10% b. 50% c. 80% d. 90%

D. 90%

Explain how a small amount of chlorofluorocarbons can destroy a large amount of ozone.

The chlorine in chlorofluorocarbons is broken from the molecule by ultraviolet radiation. The free chlorine then combines with an oxygen atom from ozone, leaving an oxygen molecule and forming chlorine monoxide. Free molecules of oxygen can displace the chlorine in chlorine monoxide, leaving chlorine free to break up another molecule of ozone. One chlorine atom can destroy up to 100,000 ozone molecules.

How does the ozone layer help maintain ground-level air quality?

The ozone layer absorbs a large portion of incoming UV radiation, which keeps ground-level ozone from forming. A higher percentage of UV radiation entering the troposphere would allow a greater amount of ozone to form in the troposphere. Ozone is a pollutant in the troposphere. By regulating the amount of UV radiation that enters the troposphere, the ozone layer also regulates the amount of ozone formation in the troposphere.

Explain the role of the ozone layer in sustaining life on Earth.

The ozone layer helps regulate the Earth's temperature by absorbing a large percentage of the UV radiation entering the atmosphere. This protects living organisms from exposure to large amounts of UV radiation, maintains livable climates, and regulates the amount of harmful ground-level ozone.

Explain how ozone in the stratosphere is formed.

Ultraviolet radiation breaks the bond between two oxygen atoms in an oxygen molecule, leaving two free oxygen atoms. When one of these free oxygen atoms combines with an existing oxygen molecule, it forms a molecule composed of three oxygen atoms, known as ozone.