- Liquid, gas, solid
Kinetic theory
- All particles are in constant motion
Solids
- Particles are close together
- Strong attraction between particles
- Hold their shape
- Cannot be compressed
- Vibrate in place, the vibrations will increase with temperature
Liquid
- There is still attraction between particles
- Particles packed tightly together
- Cannot compress or squeeze
- Take the shape of their container
- Not stuck rigidly
- More moving freely
- As temperature increases, the particles get faster
Gas
- Particles are far apart
- There is very little/to no attraction between particles
- Expands with heat
- Can compress
- Particles move in a straight line until they hit another particle or the sides of their container
All forms of matter are made up of tiny(smaller than cells) particles that:
- Cannot be squashed or compressed
- Attracted to each other
- Are constantly moving
Expansion, pressure and contraction
- As particles (solid or liquid) heat up, they move farther apart so the particles expand and take more space
- If gas is inside a container, it will cause the particles to move faster, hit the container more and therefore increase the pressure. This is when temperature increases.
Changing from states of matter
- As temperature increases, particles move faster and farther apart
- There is enough energy for the particles to move because of the heat.
- Melting and freezing(particles in a solid will eventually lose shape because they are moving too fast)
- Evaporation and Condensation(Particles are moving so fast that they escape the liquid state)
Chemical and Physical changes
- Reversible change: temporary change
- Irreversible change: permanent change
- During a chemical change, a new substance/substances has to be formed. This is an irreversible change.
- The starting substances used in a reaction are reactants.
- The new substances formed in a reaction are products
- We show reactions with an arrow. The arrow means “change into”.
- Difficult to reverse a chemical reaction and change the products back into the reactants.
- Many reactions need energy to get them started
- Some reactions give out heat energy once the reaction has started.
- Heat energy being given out is one sign of a chemical reaction
- Particles are in constant movement
- During a physical change, the substance is still the same, but its state of matter changes. This is a reversible change
- Physical Change
- Change in size, state, shape or appearance of matter
- Chemical change
- Causes matter to become a new type of matter