changes of state and particle model

• if you touch a live wire you get electrocuted because the potential difference of the wire is larger than the potential difference of your body, therefore the large difference makes you get a shock
• in a solid the forces between the particles are stronger than the forces between the particles in a liquid
• gases are easy to compress because they have large gaps between the particles, therefore the particles are easier to push closer together
• in a solid, particles vibrate in fixed positions and are closely packed
• in a gas the particles move fast and in random directions and are far apart
• specific latent heat of vaporisation is the amount of energy required to change the state of a substance from liquid to gas
• evaporation causes the cooling of water, this is because the faster particles have enough energy to escape the surface of the water, so the mean energy for remaining particles decreases, so the lower the mean energy of particles, the lower the temperature of the water
• specific latent heat of fusion is the amount of energy required to change the state of a substance from solid to liquid until the mass is 1kg