system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Can you increase the speed of sound by using different gasses?

Is there a gas that moves quicker than Co2, or is the movement of gases by pressure waves a constant force?
gpt
The speed of sound is increased if the density of the gas is lower. For example, in helium, the speed of sound is 1007m/s at atmospheric pressure and 20°C, almost three times as much as in air. In a heavy gas like xenon, it's only 178 m/s.

That is because the less dense gas is easier to push, while the force created by the pressure doesn't change.