Question

The predominant gas present in the atmosphere is:

• A. Propane
• B. Butane
• C. Carbon monoxide
• D. Carbon dioxide

Hint:

The Earth's atmosphere is mainly Nitrogen and Oxygen. Gases like CO2 are present in very small amounts (parts per million), but they can have a large impact on the climate.

Answer 1

The Correct Option is D

The question's phrasing is suboptimal. Nitrogen constitutes approximately 78% of the atmosphere, followed by Oxygen at 21% and Argon at 0.9%. The provided options are all trace gases.

Carbon dioxide ($CO_2$): \(\sim\)420 ppm (0.042%)
Carbon monoxide (CO): Variable, around 0.1 ppm
Propane ($C_3H_8$) and Butane ($C_4H_{10}$): Extremely low concentrations, at sub-ppb levels.
Among the available choices, Carbon dioxide has the highest concentration.