Choose the answer that best explains what happens to the weight of the substances after a chemical reaction occurs.
A. The weight of the substances have changed after a chemical reaction occurs, because they have gone through a physical change.
B. The weight of the substances before and after a chemical reaction stay the same, because even though the substances may change form, the weight of each atom does not change.
C. The weight of the substances have changed, because the atoms of the substance have changed.