physics
| Front | How can a gas be compressed or expanded by pressure changes? |
| Back | Gas particles are far apart in nature, with empty space between them, so increasing pressure forces particles to be closer together, so they therefore decrease in volume, which is compression. |
| Front | movement of particles in a gas |
| Back | not touching, free to move randomly |
| Front | equation for density |
| Back | density (kgm^-3) = mass (kg) / volume (m^3) |