Balancing Chemical Equations

What does the Law of Conservation of Mass say? It says,

"During a chemical reaction, mass is neither _______ or destroyed."

The substances that go into a reaction are called the _______.

So, the Law of Conservation of Mass would tell us that the mass of all the REACTANTS must __________ the mass of all PRODUCTS in a chemical reaction.

An ENDOTHERMIC reaction would feel ______ to the touch, while an EXOTHERMIC reaction would feel ______ to the touch.