Atoms 1.8 explain how information from chromatograms can be used to identify the composition of a mixture.

Chromatography

Chromatography can be used to separate mixtures of coloured compounds.

Simple chromatography is carried out on paper. A spot of the mixture is placed near the bottom of a piece of chromatography and the paper is then placed upright in a suitable solvent, e.g. water.
As the solvent soaks up the paper, it carries mixtures with it. Different components of the mixture will move at different rates, this separates the mixture out. 

Atoms 1.6 understand the differences between elements, compounds and mixtures

Elements, compounds and mixtures

Elements and compounds have their own chemical properties. The properties of a compound are likely to be different from the elements that have been used to make it. A mixture will have the properties of each substance been used to make it.

Elements- Only one substance, all elements are listed on the periodic table. e.g Na, O, Fe

Molecules- 2 or more elements bonded e.g NaCl, MgO

Mixtures- 2 or more elements that have not been bonded together e.g Iron and sulfur