Types of Matter: Pure Substances and Mixtures

• Matter can be divided into pure substances and mixtures, based on the number of different subunits it contains.

Pure Substances

• Pure substances are substances that are made up of one type of subunit.

• This subunit may be an atom or a molecule.

Pure substances contain only one type of subunit.

Mixtures

• Mixtures are substances that are made up of more than one type of subunit.

• Mixtures are physical combinations of two or more pure substances.

Mixtures contain more than one type of subunit.