Oxygen atoms: Oxygen atoms are the individual particles that make up molecules of oxygen gas (O₂). They have eight protons in their nucleus and are essential for many chemical reactions.
Aluminium oxide: Aluminium oxide (Al₂O₃) is a compound formed by the reaction between aluminium and oxygen. It is commonly known as alumina.
Aluminium sulfate: Aluminium sulfate (Al₂(SO₄)₃) is another compound containing aluminium. It is used in water treatment processes and as a preservative in some foods.