Kinetic Theory - The Solid State

Solids, liquids and gases are all made out of tiny bits and pieces: or particles. Sometimes the particles are just single atoms, and at other times the particles are collections of atoms called molecules. Whatever they are made out of, these particles are always moving.


Even the particles in a solid move around - but not much

The particles that make up the solid are always vibrating from side to side and up and down. If you give a solid some energy then the particles will move around a little bit more. This is what happens when you heat up a solid piece of wax - give it too much heat and the solid wax will turn into a liquid (or melt).

solid particles vibrate about a fixed point

The particles in a solid do move - they just don't move from one position to another. The amount of movement depends on the amount of energy in the particles.

Now answer these questions ...

  1. All solids, liquids and gases are made out of what ?
  2. Are the particles moving or still ?
  3. Do the particles in a solid move ?
  4. What do you give a solid to make the particles move more ?
  5. What sort of energy could you give wax to turn it into liquid ?
  6. When they are hot do the particles move more or less ?
  7. What is the name of the process in which a solid turns into a liquid ?
  8. Do the particles in a liquid move more or less ?
  9. If you took energy out of a liquid would it turn into a gas or a solid ?
  10. What is the name of the process in which liquid water turns into solid ice ?

You scored out of 10 on that test

the particles in a solid are similar to gears in an engine

  • The particles in a solid are attracted together by strong bonds. This makes sure that the particles can move a little bit but they are not able to escape from their neighbours.
  • It is these bonds in a solid that hold the particles together. The bonds between the particles stop the solid from spreading out to take up the shape of the container that they are in.
  • The bonds also mean that you can't pour a solid, neither does the solid flow if you put it on a slope.
  • So, the particles in a solid do move but they don't move about; you can't pour a solid; a solid doesn't flow; and a solid doesn't take up the shape of a container. This is all because of the bonds holding the particles in a solid together

... and now these questions

  1. Are the particles in a solid moving or still ?
  2. The particles are attracted by strong what ?
  3. The bonds means that the particles can't escape from other what ?
  4. The bonds stop the solid from taking up the shape of what ?
  5. A solid on a slope will not do what ?

You scored out of 5 on that test