Density
Density describes how closely packed the particles are in a solid, liquid or gas.
All Sub-atomic particles and anything made from them, such as atoms and molecules, are matter. Energy and forces are not matter. contains particles. The difference between the different states of matter is how the particles are arranged:
- in a solid – particles are tightly packed in a regular structure
- in a liquid – particles are tightly packed but free to move past each other
- in a gas – particles are spread out and move randomly
Changing the state of a material will change its density
There is little difference between the density of a liquid and its corresponding solid (eg water and ice). This is because the particles are tightly packed in both states. The same number of particles in a gas would spread further apart compared to in the liquid or solid states. The same mass takes up a bigger volume - this means the gas is less dense.
