Reactants:
* What they are: The substances that are present *before* a chemical reaction takes place.
* What they do: They undergo a chemical change, transforming into new substances.
* Where they are: Found on the left side of a chemical equation.
* Example: In the reaction of hydrogen gas (H2) and oxygen gas (O2) to form water (H2O), H2 and O2 are the reactants.
Products:
* What they are: The substances that are formed *after* a chemical reaction takes place.
* What they do: They are the result of the chemical change that happened to the reactants.
* Where they are: Found on the right side of a chemical equation.
* Example: In the reaction of hydrogen gas (H2) and oxygen gas (O2) to form water (H2O), H2O is the product.
In a nutshell:
* Reactants are the starting materials.
* Products are the ending materials.
Key Point: In a balanced chemical equation, the number of atoms of each element on the reactants' side must equal the number of atoms of the same element on the products' side. This ensures the law of conservation of mass is upheld.
