STATE CHANGES

=State Changes= '''Matter can exists in three state; solid, liquid or gas.''' [image:http://i.imgur.com/xgbohW2.png?1] ===Changes in temperature can cause a substance to change from one state to another=== [image:http://i.imgur.com/g86Tlpx.png] '''Melting''': Particles in a solid are held together by strong attractive forces (known as chemical bonds). Heating the solid gives the particles more energy and they begin to vibrate faster. If the solid is heated to a high enough temperature, the particles gain enough energy to break free from these bonds and they start to slide over each other (a liquid). '''Boiling / Evaporation''': When a liquid is further heated, the particles move faster and actually gain enough energy to break free from each other entirely (a gas). '''Condensing''': This is the reverse of evaporation. When a gas is cooled the particles lose energy and slow down. Eventually they become so slow that they stick together and can only slide over each other (a liquid). '''Solidification / Freezing''': This is reverse of melting. As a liquid is cooled, the particles lose energy and slow down. Eventually they lose so much energy that they can only vibrate in a fixed position (a solid). '''Sublimation''': Some substances don’t pass through the liquid phase at all. They skip the liquid phase and can jump straight from a gas to a solid and vice versa. This is known as sublimation. For instance ‘Dry Ice’ sublimes from a solid straight into a gas (that’s why its called dry ice, because it’s never wet!).