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 is poorly phrased. The most predominant gas in the atmosphere is Nitrogen (78%), followed by Oxygen (21%) and Argon (0.9%). All the options provided are 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, sub-ppb levels.
Of the choices given, Carbon dioxide is the most abundant.