Which gas makes up approximately 78 percent of Earth's atmosphere?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Prepare for the Instrument Flying Exam. Utilize flashcards and multiple choice questions, each with hints and explanations. Ensure readiness for your test!

Multiple Choice

Which gas makes up approximately 78 percent of Earth's atmosphere?

Explanation:
Understanding the composition of Earth's atmosphere by volume is what this item probes. Nitrogen is the most abundant gas, making up roughly 78 percent of dry air at the surface. Oxygen is the next most plentiful, about 21 percent, and the rest of the gases—including argon and carbon dioxide—occur only in trace amounts. Therefore, the figure 78 percent points to nitrogen as the correct answer. Keep in mind these values refer to dry air at sea level; when humidity is higher, water vapor adds a little more volume and can slightly reduce the relative share of nitrogen, but nitrogen still dominates the mix.

Understanding the composition of Earth's atmosphere by volume is what this item probes. Nitrogen is the most abundant gas, making up roughly 78 percent of dry air at the surface. Oxygen is the next most plentiful, about 21 percent, and the rest of the gases—including argon and carbon dioxide—occur only in trace amounts. Therefore, the figure 78 percent points to nitrogen as the correct answer. Keep in mind these values refer to dry air at sea level; when humidity is higher, water vapor adds a little more volume and can slightly reduce the relative share of nitrogen, but nitrogen still dominates the mix.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy