The most abundant gas in the atmosphere is? a. oxygen b. carbon c. nitrogen d. helium
The Correct Answer and Explanation is:
Correct Answer:
c. nitrogen
Explanation
The Earth’s atmosphere is a complex mixture of gases that surrounds the planet and supports life. Among the various gases present, nitrogen is the most abundant. It constitutes approximately 78% of the atmosphere by volume. This is followed by oxygen, which makes up about 21%, while the remaining 1% is composed of other gases such as argon, carbon dioxide, neon, helium, and trace gases.
Nitrogen (N₂) is a colorless, odorless, and tasteless gas. Despite being the most plentiful, it is relatively inert under normal conditions, meaning it does not easily react with other substances. This chemical stability makes nitrogen an essential buffer in the atmosphere. It helps dilute oxygen, which is a highly reactive gas, preventing rapid combustion of materials on Earth.
The abundance of nitrogen in the atmosphere is largely due to natural processes such as volcanic activity and the nitrogen cycle. In this cycle, nitrogen is cycled between the atmosphere, the soil, and living organisms. Although nitrogen gas is not directly usable by most living organisms, certain bacteria in the soil and root nodules of legumes can fix atmospheric nitrogen into compounds like ammonia (NH₃), which plants can absorb and use to make proteins and other vital molecules.
The dominance of nitrogen also has implications for weather, climate, and aviation. Because it is lighter than oxygen and does not absorb infrared radiation effectively, it has less of a greenhouse effect compared to gases like carbon dioxide or methane.
In summary, nitrogen is the most abundant gas in Earth’s atmosphere, making up about 78%. Its stability and role in various natural cycles make it an essential component of the atmosphere and the biosphere.
Answer: c. nitrogen
