Answer;
changing the bonds changes the mass
Step-by-step explanation;
Based on the law of conservation of mass, the mass of the products in any given chemical reaction must equivalent to that of the reactants.
This particular law is vital for a number of calculations and may be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.
in this case it will be appropriate to say that changing the bonds in a chemical reaction changes the mass, simply because bonds dictate the amount of energy consumed or released in a chemical reaction.