Particles and mixtures
Chemists explain the properties and reactions of chemicals using ideas about particles. Particles range from individual atoms right up to particles that are big enough to see, like grains of sand.
Simple distillation
Distillation separates a liquid from a solution. For example, water can be separated from salty water by simple distillation. This method works because the water evaporates from the solution, but is then cooled and condensed into a separate container. The salt does not evaporate and so it stays behind.