General Science question from Panchayat Secretary (VLW) exam, 2025 by JKSSB
Which one of the following is NOT a major greenhouse gas?
Last updated Jun 5, 2026
Correct Answer:
Option A —
Oxygen
Why Oxygen is NOT a Greenhouse Gas
Greenhouse gases are gases that trap heat in the atmosphere by absorbing and emitting infrared radiation.
The Chemistry: To absorb infrared radiation, a molecule must be able to change its dipole moment (the distribution of its electrical charge) when it vibrates.
Diatomic Gases: Oxygen (O
2
) is a homonuclear diatomic molecule, meaning it consists of two identical atoms. Because it is perfectly symmetrical, its vibrations do not create a change in its dipole moment. Therefore, oxygen allows infrared radiation (heat) to pass straight through it without trapping it. The same is true for Nitrogen (N
2
), which makes up about 78% of our atmosphere.
Quick Facts About the Major Greenhouse Gases:
(B) Methane (CH
4
): A potent greenhouse gas released during the production of coal, natural gas, and oil, as well as from livestock and agricultural practices. It is much more effective at trapping heat than carbon dioxide over a short timeframe.
(C) Carbon dioxide (CO
2
): The primary greenhouse gas emitted through human activities, such as burning fossil fuels (coal, natural gas, and oil), deforestation, and industrial processes.
(D) Water vapour (H
2
O): The most abundant greenhouse gas in the atmosphere. While it isn't directly controlled by human activity like CO
2
, it acts as a powerful feedback loop—as the planet warms, more water evaporates, trapping even more heat.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
