* Formation of a new substance: When Epsom salt and ammonia are mixed, they react to form magnesium ammonium phosphate (MgNH4PO4) and ammonium sulfate ((NH4)2SO4). These are distinct chemical compounds with different properties than the original reactants.
* Release of heat or light: The reaction between Epsom salt and ammonia is exothermic, meaning it releases heat. This is another indication of a chemical change.
* Irreversible reaction: The formation of magnesium ammonium phosphate and ammonium sulfate is generally irreversible. To get back the original reactants, you would need to perform a different chemical reaction.
Therefore, the mixing of Epsom salt and ammonia leads to the formation of new substances, release of heat, and an irreversible change, all hallmarks of a chemical change.
