Which one of the following gases is released mostly from landfills in urban areas?

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Q: 1 (CDS-II/2016)

Which one of the following gases is released mostly from landfills in urban areas?

question_subject: 

Science

question_exam: 

CDS-II

stats: 

0,53,37,7,9,73,1

keywords: 

{'gases': [0, 0, 5, 12], 'landfills': [0, 0, 0, 2], 'methane': [0, 0, 0, 5], 'nitrogen': [1, 1, 0, 2], 'oxygen': [3, 0, 1, 0], 'hydrogen': [0, 0, 1, 3], 'urban areas': [0, 0, 0, 1]}

The correct answer is option 3 - Methane. Methane is the gas that is primarily released from landfills in urban areas.

To understand why methane is released from landfills, we need to consider the process of decomposition. When organic waste, such as food scraps and yard waste, is thrown into a landfill, it undergoes anaerobic decomposition. Anaerobic decomposition occurs in the absence of oxygen, and it produces methane gas as a byproduct.

Methane is a greenhouse gas that contributes to global warming and climate change. It has a much higher global warming potential compared to carbon dioxide, making it a significant concern for environmental impact.

The other options - Nitrogen, Hydrogen, and Oxygen - are not released primarily from landfills. Nitrogen is a component of the Earth`s atmosphere and is not specifically associated with landfills. Hydrogen is a highly flammable gas and is not commonly released from landfills. Oxygen is also not released in significant amounts from landfills, as the decomposition process occurs in an oxygen-deprived environment.