Final answer:
The Law of Conservation of Mass, formulated by Antoine Lavoisier in 1789, states that matter cannot be created or destroyed in a chemical reaction, ensuring the mass of reactants equals the mass of products.
Step-by-step explanation:
The Law of Conservation of Mass states that in any chemical reaction, matter is neither created nor destroyed. This principle indicates that the total mass of the reactants must equal the total mass of the products. A classic example of this law is the reaction between hydrogen and oxygen to form water. No matter how the two gases combine, if you start with 2 grams of hydrogen and 16 grams of oxygen, you will end up with 18 grams of water (2 grams + 16 grams = 18 grams). The mass remains constant before and after the reaction.
This conservation principle was put forth by French chemist Antoine Lavoisier in 1789, and it forms the basis of chemical stoichiometry, allowing chemists to predict the amounts of products that will form in a given reaction. It is important to note that this law applies in a closed system where no mass is allowed to enter or leave the system during the reaction.