Units 9, 10, and 11: Particles, temperature, and everything in between

I'm sure everyone is familiar with the 3 states of matter: solid, liquid, and gas. (there are actually 4 states of matter with plasma being the 4th, but who cares? cambridge doesnt)

I'll let the images do the talking for now so we can skip to the good parts

memorise all this and remember that solid has the least energy because their particles vibrate/move the least because they have less kinetic energy. Gas has the most energy. This is why you need to heat a solid to melt it into a liquid and heat a liquid to boil it into a gas. (Overcome intermolecular forces of attraction)

You should also know that the random movement of liquid or gas particles is called Brownian motion, which is proven when air particles collide with smoke particles, sending them in random directions with random speeds.

Remember absolute zero is at -273˚C, or 0 kelvin.

Pressure and volume are related by P1V1 = P2V2

As it is a common 3 or 4 mark question, you should know how particles exert a force on their container walls.

1. Particles/Molecules move in random directions at random speeds (brownian motion)

2. Particles collide with container walls and bounce off

3. Particle experiences a change in momentum

4. which will exert a force on the container

Increasing the temperature also increases pressure because particles have more KE and collide more.

Solids, liquids and gases expand when temperature increases, contract when temperature decreases. Solids expand the least, gases expand the most.

Thermal expansion can be problematic such as the bending of train tracks or bridges, but is useful because thermometers use it to work.

Know the difference between boiling and evaporation:

It is important to note that during change of state, temperature does not change because all the thermal energy is being used to change state.

The energy needed to raise the temperature of 1kg of a substance by 1˚C is the specific heat capacity. Don't get it mixed with thermal capacity or specific latent heat. Anyways, all of those are in the formula sheet.

Infrared radiation transfers thermal energy. It can travel through space as it is an EM wave.

Different surfaces absorb and emit radiation differently. Shiny white surfaces reflect the most, so they heat up the slowest. Matte black surfaces absorb and emit radiation the fastest, so they got hot quickly.

Metals are conductors because they have a sea of free moving electrons which can carry the heat.

Most non-metals are insulators (do not conduct heat)

In fluids, heat can travel through convection.

This is because hot fluids are less dense than cold fluids.

That's it for now. It is important to note that I have omitted certain details to make this as concise and helpful as possible. If there is something I have not covered here, feel free to leave a comment in the forums.