P3 - Particle Model of Matter - Paper 1

2. Energy: the energy particles have due to their positions relative to each other.
4. Changes to the chemical structure of a substance. The substance does not usually restore its original properties when the changes are reversed.
5. The changing from vapour state to a liquid state, when a substance is cooled.
8. no fixed volume or shape, has almost no forces of attraction between
9. No fixed shape but has a fixed volume with weak forces of attraction between particles
10. The changing from solid state to liquid state, when a substance is heated.
12. The direct changing of a substance from a solid state to a vapour state, without passing through the liquid phase.
13. The amount of energy needed to increase the temperature of one kilogram of a given substance by one degree Celsius.
14. The energy stored by the atoms and molecules that make up a system. It is equal to the sum of the total kinetic and potential energies of the particles in the system.
15. has a fixed volume and shape, with strong forces of attraction
18. for a fixed mass of particles at a constant temperature the pressure is inversely proportional to the volume of gas
19. The mass per unit volume of an object.
21. the energy store that represents the motion of the particles and is linked to the temperature of the particles

1. The amount of energy needed to change the state of one kilogram of a substance, whilst held at constant temperature.
3. The unit of pressure, equal to a force of one Newton acting perpendicular to an area of one metre squared.
6. The changing from liquid state to a vapour state, when a substance is heated.
7. The changing from a liquid state to a solid state, when a substance is cooled.
11. The temperature of a gas is directly proportional to the average kinetic energy of its molecules.
16. Changes to the physical properties of a substance which can be reversed.
17. The energy required for a substance to change state.
20. The force acting perpendicular to a surface, per unit area.