During a [blank_start]chemical[blank_end] reaction, the atoms within substances are rearranged and joined together in different ways. This results in a substance that is completely [blank_start]different[blank_end] to the original substances.
The original substances are called [blank_start]reactants[blank_end] and their original [blank_start]properties[blank_end] change as the reaction takes place.
The new product formed from a chemical [blank_start]reaction[blank_end] can only be separated again by another chemical reaction because the [blank_start]particles[blank_end] are chemically linked.