Type of reaction with reference to oxygen and hydrogen are oxidation reaction and reduction reaction.
Oxidation reaction: The chemical reaction in which a reactant combines with oxygen or loses hydrogen to from the product is called Oxidation reaction.
e.g. `2Mg+O_(2) to 2MgO`
Here`O_(2)` combines with magnesium (Mg) to form nagnesium oxide (MgO)
`MgH_(2) to Mg+H_(2)`
Here `MgH_(2)` loses hydrogen.
Reduction reaction: The chemical reaction in which a reactant combines with hydrogen or loses oxygen to form product is called reduction reaction.
e.g.` C+2H_(2) to CH_(4)`
Here carbon combines with hydrogen and forms compound `CH_(4)` (Methane).
`HgOoverset(Delta)to Hg+ O_(2)`
Here Mercuric oxide loses oxygen to form marcury.