At first, they differ because a physical property is observed without changing the nature of the substance. On the other hand, a change in the nature of the substance must be carried out to observe a chemical property.
As examples, density, solubility and odor (physical properties) could be known by just analyzing a substance, nonetheless, pH, reactivity or combustibility must be known by submitting the substance to a specific chemical reaction.
Ferric oxide reacts with aluminium to produce aluminium oxide and iron. The balanced chemical equation for the given reaction is : Fe2O3 + 2Al → Al2O3 + 2Fe.
