The correct option is (c).
Explanation
The atmosphere is a mixture of various gases essential for life and Earth's physical processes. The composition of air is dominated by Nitrogen and Oxygen, with other gases present in trace amounts.
Statement-wise Analysis:
- Statement 1 is Incorrect. Carbon Dioxide (CO2) constitutes a very small fraction of the atmosphere, approximately 0.04%. The largest component of air is Nitrogen (approximately 78%), followed by Oxygen (approximately 21%) and Argon (approximately 0.93%).
- Statement 2 is Correct. Carbon Dioxide is a metabolic byproduct produced by both plants and animals during respiration. In this process, organisms consume oxygen to break down organic compounds for energy, releasing CO2 into the atmosphere.
- Statement 3 is Correct. In a closed or poorly ventilated room, processes like respiration or combustion can lead to the accumulation of CO2. Elevated levels of CO2 displace oxygen and can cause suffocation, dizziness, and respiratory distress due to oxygen deprivation and hypercapnia (toxicity caused by excessive CO2).
Key Takeaway:
Nitrogen is the most abundant gas in the atmosphere. Carbon Dioxide is a trace gas released during respiration; however, its accumulation in confined spaces is hazardous to health.