Points to Remember:
- The question tests knowledge of atmospheric composition.
- We need to identify which gas is not naturally occurring in the Earth’s atmosphere.
Introduction:
The Earth’s atmosphere is a complex mixture of gases that are essential for life. The major components are nitrogen (approximately 78%), oxygen (approximately 21%), and argon (approximately 1%). Trace gases, present in smaller quantities, include water vapor, carbon dioxide, neon, helium, krypton, and xenon. The relative proportions of these gases have varied throughout Earth’s history, influenced by geological processes and biological activity. However, the introduction of certain synthetic gases has significantly altered the atmospheric composition in recent times, leading to environmental concerns.
Body:
Identifying Naturally Occurring Atmospheric Gases:
The question asks us to identify a gas that is not a natural element of the atmosphere. Let’s examine the options:
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(A) Chlorofluorocarbon (CFC): CFCs are synthetic compounds, entirely human-made. They were widely used in refrigerants, aerosols, and other applications until their damaging effects on the ozone layer were discovered. CFCs do not occur naturally in the atmosphere.
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(B) Argon: Argon is a noble gas and constitutes about 1% of the Earth’s atmosphere. It is naturally occurring and a product of radioactive decay within the Earth’s crust.
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(C) Krypton: Krypton is another noble gas present in trace amounts in the atmosphere. It is naturally occurring.
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(D) Water vapor: Water vapor is a variable component of the atmosphere, its concentration depending on temperature and location. It is naturally occurring through the hydrological cycle (evaporation, condensation, precipitation).
Analysis of Options:
Based on the above analysis, only Chlorofluorocarbon (CFC) is not a naturally occurring element of the atmosphere. All other options â?? Argon, Krypton, and Water vapor â?? are naturally present in the Earth’s atmosphere.
Conclusion:
The correct answer is (A) Chlorofluorocarbon. While Argon, Krypton, and Water vapor are naturally occurring components of the Earth’s atmosphere, CFCs are entirely synthetic. The introduction of CFCs and other synthetic gases into the atmosphere has had significant environmental consequences, highlighting the importance of understanding and managing human impacts on the delicate balance of Earth’s atmospheric composition. Moving forward, continued research and stringent regulations on the production and release of harmful synthetic gases are crucial for protecting the environment and ensuring a sustainable future for all. This underscores the need for a holistic approach to environmental protection, prioritizing the preservation of our planet’s natural systems.