C) Pressure will compress a gas, reducing its volume and giving it a greater density and concentration of particles.
Let's look at the available choices and determine why or why not they're correct.
A) Pressure will expand a gas, enlarging its volume and reducing its density and concentration of particles.
* What? So increasing the pressure on a gas will make it take up a larger volume? That definitely doesn't match the world I live in. I hope that's true for you as well. Wrong choice.
B) Pressure will magnify a gas, developing its volume and multiplying its density and concentration of particles.
* Lots of interesting sounding words, but they're mostly used in a nonsense fashion. Useful if you're easily fooled by technobabble, but it's another wrong answer.
C) Pressure will compress a gas, reducing its volume and giving it a greater density and concentration of particles.
* OK. Increasing the pressure will compress a gas. So it has a smaller volume. And since it still has the same mass, the density will become greater. And the particles closer together. Everything here matches reality. Good choice.
D) Pressure will accelerate a gas, extending its volume and allowing a smaller density and concentration of particles.
* Most technobabble. Why would the gas be accelerated? No reason that I know of. Wrong choice.
