Stratospheric Ozone Depletion

Which chemical that replaced CFCs in refrigerants is now a concern as a major greenhouse gas?

• CFCs

• HFCs

• DDT

• CFCl2

Second layer of the atmosphere, extending about 17-48 kilometers above the earth’s surface. It contains a layer of gaseous ozone, which filters out about 95% of the incoming harmful ultraviolet radiation emitted by the sun

• Mesosphere
• Troposphere
• Stratosphere
• Ozone

Layer of gaseous ozone in the stratosphere that protects life on earth by filtering out most harmful ultraviolet radiation from the sun

• Greenhouse Gases
• Troposphere
• Stratosphere
• Ozone Layer

Which of these sets of three items produce CFCs

• cars, factories, and cardboard
• spray cans, cardboard, insulation
• spray cans, refrigerant, cardboard
• spray cans, refrigerant, insulation

Though CFC production has been curtailed, the threat to upper atmosphericozone continues because CFCs

• become harmless quickly.
• destroy ozone for only a short time.
• persist but stop destroying ozone.
• persist and continue to destroy ozone for decades.

Which is most strongly absorbed by ozone in the statosphere?

• UV-A

• UV-B

• UV-C

• UV-B and UV-C

• UV-A and UV-B

How do CFCs affect ozone production?

• UV radiation frees a chlorine atom, which breaks down ozone.
• Infrared radiation frees a chlorine atom, which breaks down ozone.
• UV radiation frees a fluorine atom, which breaks down ozone.
• Infrared radiation frees a chlorine atom, which breaks down ozone.

Through international cooperation, the concentration of chlorine in the atmosphere

• has already decreased below 3ppb
• will stabilize around 3ppb by 2030
• has stabilized at 5ppb
• is expected to stabilize at 5ppb by 2100

When is the ozone hole largest?

• early Antarctic spring

• late Antarctic summer

• early Antarctic winter

• late Antarctic fall

The formation of ozone begins when and O2 molecule is split by

• UV-A radiation
• UV-B radiation
• UV-C radiation
• UV-A or UV-B radiation