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Which of the following statements is/are correct related to eco-system? (i) UV radiation is not damaging to organisms. (ii) Ozone at the higher levels of the atmosphere is a product of UV radiation acting on oxygen molecule. (iii) The amount of ozone in the atmosphere began to drop sharply in 1980.
Only (ii) and (iii)
(i), (ii) and (iii)
Only (i) and (ii)
Only (i)
Only (ii) and (iii)
Statements (ii) and (iii) are scientifically correct. Ozone (O3тАЛ) at the higher levels of the atmosphere is formed by the action of UV radiation on oxygen molecules (O2тАЛ), and the atmospheric ozone layer began to show a significant depletion, starting mainly in the 1980s, primarily due to chlorofluorocarbons (CFCs).
Statements (ii) and (iii) are scientifically correct. Ozone (O3тАЛ) at the higher levels of the atmosphere is formed by the action of UV radiation on oxygen molecules (O2тАЛ), and the atmospheric ozone layer began to show a significant depletion, starting mainly in the 1980s, primarily due to chlorofluorocarbons (CFCs).
Think of the ozone layer as Earth's 'sunscreen'тАФit blocks harmful rays. If you thin out this sunscreen (ozone depletion), more harmful radiation reaches the surface, just as you'd get a sunburn if you applied too thin a layer of protection.
O-Zone formation: 'O-2 gets split by UV, then joins another to make O-3.'
O2тАЛ+UVтЖТO+O тАФ Photodissociation of oxygen
O+O2тАЛтЖТO3тАЛ тАФ Formation of ozone
In the stratosphere, high-energy UV radiation splits oxygen molecules into individual oxygen atoms: O2тАЛ+UVтЖТO+O. These highly reactive atoms then combine with remaining oxygen molecules to form ozone: O+O2тАЛтЖТO3тАЛ. UV radiation is harmful to living organisms as it can cause DNA damage, skin cancer, and cataracts.
UV radiation is harmful and causes DNA mutation, skin cancer, and cataracts.
Ozone is a triatomic molecule (O3тАЛ) that acts as a shield against UV rays.
Ozone depletion is primarily caused by synthetic chemicals like CFCs.
The Antarctic ozone hole discovery in the 1980s highlighted the impact of human activities.
Ozone layer protects life by absorbing lethal UVC and most UVB radiation.
Ozone near the ground is a pollutant and hazardous to respiratory health.
UV sterilization in water treatment
Atmospheric protection of the biosphere
Statement (i) is incorrect because UV radiation (specifically UVC and UVB) is highly damaging to living organisms.
The 1987 Montreal Protocol was a historic treaty signed to phase out the production of substances responsible for ozone depletion.
A is correct тАФ Statements (ii) and (iii) accurately describe the chemical formation of ozone and the historical context of its depletion.
Always remember that UV is high-energy electromagnetic radiation; it is ionizing enough to break chemical bonds, which is why it is dangerous to biology.
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