Basic Chemistry/Physical changes
Physical changes don't change the particles themselves - only their arrangement or their energy.
Changes of state
This is changing from one state of matter to another.
Gas pressure is due to particles hitting a surface.
- When you increase the temperature, it makes particles move faster. This has two effects:
- The particles hit the surfaces harder, and
- more often.
- This increases the pressure.
- When you reduce the volume of the container in which the gas is contained, the pressures also increases. This is because the particles become more squashed up in a smaller space, so they hit the surfaces more often.
Diffusion is particles spreading out. Also, Diffusion is the movement of particles from a lower point of concentration to a higher point of concentration
NOTE: temperature is a major determinant of how fast a particle diffuse. Particles in a solid state don't diffuse
- It's typically slow, for example a smell spreading slowly across a room.
- The smell particles move away from where there are lots of them towards areas where there's only a few of them.
- It's slow because there are also lots of air particles getting in the way of the smell particles.