Question 26

Nitrogen (N₂) makes up 78% of Earth's atmosphere.

Approximately 78% of Earth's atmosphere consists of nitrogen (N₂), making it the most abundant gas in the atmosphere.

A) 5%

This option is incorrect as it significantly underestimates the amount of nitrogen present in the atmosphere. Nitrogen comprises a much larger percentage, rendering this choice inaccurate.

B) 21%

While this option is a common misconception, it represents the approximate percentage of oxygen (O₂) in the atmosphere, not nitrogen. Thus, this option does not correctly answer the question regarding the nitrogen content.

C) 55%

This figure is also incorrect, as it greatly overestimates the percentage of nitrogen in the atmosphere. The actual concentration of nitrogen is much lower than this value, making this option invalid.

D) 78%

This option is correct, as it accurately reflects the composition of Earth's atmosphere, where nitrogen (N₂) constitutes approximately 78%. This high percentage is crucial for various biological and chemical processes on Earth.

Conclusion

The correct answer is option D, which states that nitrogen makes up 78% of Earth's atmosphere. All other options either underestimate or overestimate the nitrogen concentration, demonstrating a lack of understanding of atmospheric composition. This reinforces the importance of accurate knowledge regarding the gases that make up the atmosphere.