particle mpdel of matter

• density tell us the mass for a given volume
• solids usally have a high density as they have many particles close together
• to measure the volume or an irregular object, out it in a eueak can that is filled with water and measure the volume of water that is displaced
• particles have potential energy from the intermoleuclar forces
• internal energy is the energy stored in a system by the particles, it is the total kinetic and potential energy in all the particles
• on those graphs, the flat part is when the substance is changing state because the energy is being used to break the bonds rather than increase the tempreature
• gases exert a pressure when they collide with the walls of a container
• to increase pressure, energy must be increased which increases the kinetic energy of the particles
• particle collisions cause a force which acts at right angles to the surface of the container
• the pressure of a gas is inversely proportional to the volume
• specific latent heat is the energy a substance needs to change state (1kg)

  fusion = solid to liquid

  vaporisation = liquid to vapour (gas)