Final answer:
The Earth's atmosphere does contain 78% N₂ and 21% O₂, but the CO₂ percentage is approximately 0.04%, not <1%. Therefore, the correct answer is B. False.
Step-by-step explanation:
The Earth's atmosphere is primarily composed of three main gases: about 78% nitrogen (N₂), around 21% oxygen (O₂), and roughly 1% argon (Ar). Additionally, the atmosphere contains traces of other gases, including water vapor (H₂O) and carbon dioxide (CO₂). However, the statement provided in the question contains a slight inaccuracy regarding the percentage of CO₂. While the atmosphere does contain < 1% CO₂, the accurate amount is about 0.04%, not up to 1%. Therefore, the correct answer would be B. False, as the CO₂ composition part of the question is not accurate.