Question

Carbon dioxide and water vapor are variable gases because _____.

their amounts vary throughout the atmosphere

they only make up 1% of the atmosphere

sometimes they're in the atmosphere, sometimes they're not

one gas depends on the other gas

Answer 1

There are two types of gases - Constant gases and variable gases.

Constant gases have almost uniform concentrations through out the Earth's atmosphere. Nitrogen, Oxygen and Argon are constant gases.

Variable gases are present in very low and variable concentrations in the Earth's atmosphere. These variable gases have deep impact on the atmosphere.

Therefore, the correct answer is their amounts vary through out the atmosphere.

Answer 2

Carbon dioxide and water vapor are variable gases because their amounts vary throughout the atmosphere.