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All 15 Flashcards — The ozone layer
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Question
Define ozone (O3).
Answer
Ozone is a molecule made of three oxygen atoms (O3). In the stratosphere it forms a layer that absorbs harmful UV radiation.
💡 Hint
Three oxygen atoms.
Question
Where is the ozone layer located and what is its main function?
Answer
It is located in the stratosphere and its main function is absorbing harmful UV radiation (especially UV-B and UV-C).
💡 Hint
Stratosphere + UV protection.
Question
Which type(s) of UV radiation are mostly absorbed by the ozone layer?
Answer
The ozone layer absorbs all UV-C and most UV-B. UV-A mostly reaches Earth’s surface.
💡 Hint
UV-C fully; UV-B mostly.
Question
Give two human health impacts of increased UV-B exposure.
Answer
Examples include higher skin cancer risk, cataracts, and immune suppression.
💡 Hint
Any two: cancer, cataracts, immune.
Question
What is the key difference between stratospheric ozone and tropospheric ozone?
Answer
Stratospheric ozone is beneficial (absorbs UV). Tropospheric ozone is a pollutant (smog) that harms human health and plants.
💡 Hint
Good up high, bad nearby.
Question
What does “good up high, bad nearby” mean for ozone?
Answer
Ozone in the stratosphere is protective; ozone at ground level (troposphere) is a pollutant and respiratory irritant.
💡 Hint
Location changes impact.
Question
Give one ecosystem-level impact of increased UV-B on aquatic systems.
Answer
UV-B can reduce phytoplankton productivity and survival, weakening the base of marine food chains and reducing carbon uptake.
💡 Hint
Phytoplankton = base of food webs.
Question
In which atmospheric layer is the ozone layer mainly found?
Answer
The ozone layer is mainly in the stratosphere (roughly 15–35 km altitude).
💡 Hint
Stratosphere.
Question
Which UV band is completely absorbed before reaching Earth’s surface?
Answer
UV-C is completely absorbed by ozone and oxygen in the atmosphere.
💡 Hint
UV-C.
Question
Describe the basic formation of ozone in the stratosphere.
Answer
UV splits oxygen molecules (O2) into O atoms; an O atom combines with O2 to form O3. Ozone also breaks down naturally, creating a dynamic equilibrium.
💡 Hint
UV splits O2 first.
Question
Name two key consequences of ozone depletion.
Answer
Increased UV-B exposure leading to more skin cancer/cataracts and reduced productivity or survival of sensitive organisms (e.g., phytoplankton).
💡 Hint
Health + ecosystems.
Question
Why are phytoplankton often highlighted in ozone depletion questions?
Answer
They are exposed near the surface, can’t escape UV easily, are the base of ocean food webs, and are an important carbon sink.
💡 Hint
Food web + carbon sink.
Question
Give one non-living (material) impact of increased UV radiation.
Answer
UV can degrade plastics, paints, rubber, and building materials faster, shortening product lifespan.
💡 Hint
Materials break down faster.
Question
Why should you not confuse the ozone layer with the greenhouse effect?
Answer
They occur in different layers and have different roles: ozone (stratosphere) absorbs UV; greenhouse effect (troposphere) traps long-wave radiation to warm Earth.
💡 Hint
Different layer, different function.
Question
Why are ozone depletion and climate change different problems?
Answer
Ozone depletion is mainly caused by ozone-depleting substances (e.g., CFCs) reducing stratospheric ozone, while climate change is driven by greenhouse gases increasing heat trapping.
💡 Hint
Different gases, different mechanisms.
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Topic 6.4 hub
Stratospheric ozone
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