Pure Substances and Mixtures

• Chemistry is the study of the physical and chemical properties of matter.

• Matter can be divided into pure substances and mixtures.

• Pure substances have fixed physical and chemical properties, such as melting and boiling point, and chemical reactivity.

Gold is a pure substance – it has fixed physical and chemical properties.

(Image: James St. John, Wikimedia Commons)

• Mixtures have variable physical and chemical properties.

• They are physical combinations of two or more pure substances, which can be physically separated.

Mud is a mixture – it has variable physical and chemical properties.

(Image: Hans, Pixabay)