Which two gases are most abundant within Earth's modern atmosphere?
A)nitrogen and oxygen
B)hydrogen and helium
C)carbon dioxide and methane
D)water vapor and sulfur dioxide

Question

Quizplus · Accepted Answer

Nitrogen and oxygen are the two most abundant gases in Earth's modern atmosphere, making up approximately 78% and 21% of the atmosphere, respectively. Hydrogen and helium are present in much smaller amounts, while carbon dioxide and methane are important trace gases, but not as abundant as nitrogen and oxygen. Water vapor and sulfur dioxide also exist in Earth's atmosphere, but their concentrations can vary widely depending on local conditions.

Which Two Gases Are Most Abundant Within Earth's Modern Atmosphere