Oxidation state facts for kids

Kids Encyclopedia Facts
Plutonium in solution
Plutonium ions in several oxidation states

Oxidation state refers to the number of electrons added to or removed from an element. Sodium metal, for example, has an oxidation state of 0 in the elemental state. But when it gives up its one valence (outer) electron (symbolized by e-), it becomes a sodium ion with an oxidation state of +1. Iron is another example. It can lose two electrons, forming an oxidation state of +2; or it can lose 3, forming an oxidation state of +3.

If elements gain electrons, they have negative oxidation states. If chlorine gains an electron, it forms a -1 ion. If sulfur gains two electrons, it forms a -2 ion.

The oxidation state determines the number of atoms of other elements that can bind to the atom.

All elements have an oxidation state of 0.

  1. oxygen has an oxidation number -2 in most of its compounds except peroxides where it has an oxidation number -1.
  2. hydrogen has oxidation state +1 in most compounds except with electropositive elements. ex: Na.
  3. alkali earth metals have oxidation state +2
  4. alkali metals have oxidation state +1

Oxidation state Facts for Kids. Kiddle Encyclopedia.