Natural Science CLEP Prep Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Study for the Natural Science CLEP Exam. Prepare with interactive quizzes and questions that cover essential concepts in natural science to ensure you're ready for test day!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the most abundant gas in Earth's atmosphere?

Helium
Hydrogen
Nitrogen
Oxygen

The correct answer is: Nitrogen

Nitrogen is the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. Helium and hydrogen are both significantly less abundant, with helium making up less than 1% and hydrogen making up less than 0.00005%. Oxygen is the second most abundant gas in Earth's atmosphere, making up approximately 21%.