Identify the true statement.

Question

Question

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AAI Junior Assistant (Fire Service) Official Paper (Held On: 15 Nov 2022 Shift 1)

An oxygen molecule is split by UV radiation, which then generates ozone molecules.
Oxygen and ozone can both absorb UV radiation to protect us from cancer.
An ozone molecule is split by UV radiation, which then generates oxygen molecules.
Oxygen and ozone are both colourless and hence do not absorb any radiation.

Answer 1

The correct answer is Option 1.

Key Points

An oxygen molecule (O₂) is indeed split by ultraviolet (UV) radiation.
This process results in the formation of individual oxygen atoms, which can then recombine with O₂ molecules to form ozone (O₃).
Ozone formation is a key part of the stratospheric ozone layer, which protects life on Earth by absorbing the majority of the sun's harmful UV radiation.
Ozone molecules (O₃) can absorb UV radiation and break down into an oxygen molecule (O₂) and a single oxygen atom (O).
This cycle of ozone formation and breakdown absorbs UV radiation and prevents it from reaching the Earth's surface, thereby protecting us from its harmful effects.

Additional Information

Ozone Layer Depletion
- Human-made chemicals like chlorofluorocarbons (CFCs) can deplete the ozone layer.
- Ozone depletion leads to increased UV radiation reaching the Earth's surface, which can cause skin cancer and other health issues.
Ozone in the Troposphere
- While stratospheric ozone protects us, ozone in the troposphere (the lowest layer of the atmosphere) is a harmful pollutant.
- Tropospheric ozone can cause respiratory problems and other health issues in humans and animals.
UV Radiation
- UV radiation is categorized into three types: UVA, UVB, and UVC.
- UVC is the most harmful but is completely absorbed by the ozone layer and atmosphere.
- UVB is partially absorbed by the ozone layer, while UVA is the least harmful and passes through the ozone layer.