Elements, Compounds

An element is any substance that is made up of only one type of atom.
Hydrogen gas is an element.
A compound is a substance that is made from two or more different types of atoms. Water is a compound.
A mixture is a substance that is made from two or more different compounds or elements. Air is a mixture.

Identify the following as a compound, element or mixture.
Each circle represents an atom. Scan the image with the cursor for the answer and more information

The diagrams A to D on the right represent the particles in different substances. Which represent a:

- pure compound?
- mixture of a compound and an element?
- mixture of elements?


Inks used in pens and texta colours appear to be composed of a single dye particle. In actual fact, the inks used in many pens are mixtures of many different inks. We can separate the different inks into their component colours by a method called thin film chromatography.

On the right is an example of three chromatograms.
"A" is the chromatogram of an orange coloured texta.
"B" is the chromatogram of an blue coloured texta
"C" is the chromatogram of a black coloured texta. All inks used are pure compounds or mixtures of compounds.

Identify which are mixtures and which are pure compounds.


Click to go to the activity on thin film chromatography.

Separating mixtures


Mixture- It is amixture of different elements. Compound-The molecules are composed of two different types of atoms Mixture- It is a mixture of elements. Mixture-We have two different types of compounds. Compound - The molecules pictured are  made up of two different types of atoms. Element -Only one type of atom is present.