Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. Draw a diagram pf particle arrangement for a solid; a liquid and a gas.
   • Solid: Particles in a pattern and close together. Liquid: Particles not in a pattern and close together. Gas: Particles not in a pattern and far apart.
2. What two things can the particle model be used to explain?
   • The Particle model can be used to explain the different states of matter differences in density.
3. In terms of particles, explain why ther are differences in density between the different states of matter.
   • Gas are significantly less dense than liquids because the same number of es are spread out over a significantly greater particlvolume in a liquid. Liquids are less dense than liquids because the same number of Particles are spread out of a slightly greater volume than in a solid.
4. What is meant by the latent heat of a substance?
   • Latent heat is the amount of Energy needed for a substance to change state.
5. What happens to the temperature when a change of state occurs?
   • When a change of state occurs, the Energy supplied changes the Energy stored (internal Energy) but not the temperature.
6. What happens to the mass of a substance as it changes state?
   • The mass of the substance is unchanged as it changes state due to the umber of Particles remaining unchanged.
7. What is the specific latent heat of a substance?
   • The specific latent heat of a substance is the amount of Energy required to change the state of one kilogram of the substance with no change in temperature.
8. How do changes of state differ from chemical changes?
   • Changes of state are physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.