Question : Which of the following is not a greenhouse gas?
Option 1: Carbon dioxide
Option 2: Water vapor
Option 3: Nitrous oxide
Option 4: Oxygen
Correct Answer: Oxygen
Solution : The correct answer is (d) Oxygen
Oxygen (O2) is not classified as a greenhouse gas because it does not possess the properties of trapping and absorbing infrared radiation emitted by the Earth's surface. Greenhouse gases, such as carbon dioxide (CO2), water vapor (H2O), and nitrous oxide (N2O), are capable of absorbing and re-emitting infrared radiation, leading to the greenhouse effect and the warming of the Earth's atmosphere. Oxygen is a vital component of the Earth's atmosphere, supporting life processes, but it does not contribute directly to the greenhouse effect.
