What are oxidation states?

The oxidation states are realated to the amount of electrons that are lost, gained or shared between atoms. This is when they form covalent or ionic bonds when forming compounds.

When a molecule is in its elemental state (eg O₂) the oxidation number is always Zero.

If they are not in their elemental state they are given a positive (+) or negative (-) sign.

  Fe →Fe³⁺+3e^-

Oxidation Number: 0      +3This is an example of an element being oxidised.

This shows that the Iron (Fe) element has lost 3 electrons and its oxidation state has increased.