Question

Unlike Venus and Mars, Earth's atmosphere is primarily composed of oxygen and nitrogen. Why is the composition of Earth's atmosphere different from the composition of the atmospheres of Venus and Mars?

A. Earth has life, while Venus and Mars do not.
B. Venus and Mars are slightly smaller than Earth.
C. Venus, Mars, and Earth all have similar chemical compositions.
D. Venus and Mars have different chemical compositions from Earth.

Answer 1

Answer: D

Explanation: The atmosphere in Venus is primarily composed by carbon dioxide (CO₂), about 2% of nitrogen (N₂) and less than 1% of Oxygen (O₂), while in Mars, besides having almost the same amount of carbon dioxide and nitrogen, it also has argonium (Ar) in its composition. Having this in mind, it's easy to notice that Earth's atmosphere and the other two planets differ in its chemical compositions, as we can see in alternative D.