The Earth's atmosphere is composed primarily of which gas?
✓ Correct Answer: Option C
Earth's atmosphere is about 78% nitrogen, 21% oxygen, and 1% other gases.
📚 About This ACT Exam Prep Practice Question
This 1-level ACT Exam Prep question from the Science topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.
How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free ACT Exam Prep practice test or use flashcards for spaced repetition review.