Elements, compounds and mixtures

Elements

• made of only one type of atom

• cannot be broken down into simpler substances by chemical methods

• fixed melting and boiling points

Compounds

• made of two or more elements chemically combined together in a fixed composition by mass

• different properties from the elements that form it

• form with an energy change

• separated by chemical methods such as electrolysis or thermal decomposition

• fixed melting and boiling point

Mixtures

• made up of two or more substances (elements and compounds) that can be separated by physical methods

• not chemically combined together

• have similar chemical properties as components

• form with little or no energy change

• can be separated by physical methods such a as filtration, distillation, evaporation, chromatography etc

• melt and boil over a range of temperatures