* New substances: This is the defining characteristic of a chemical reaction. The atoms in the reactants rearrange to form new molecules with different properties.
* Energy change: Chemical reactions either release energy (exothermic) or absorb energy (endothermic). This energy change can be in the form of heat, light, or sound.
While not always formed, it's also common for reactions to produce:
* Byproducts: These are substances that aren't the desired product but are formed as a side effect of the reaction.
It's important to remember that no new atoms are created or destroyed during a chemical reaction. This is the principle of the conservation of mass. The atoms are simply rearranged into different combinations.
