Who proposed the Law of Conservation of Mass?

Antoine Lavoisier

The correct answer is option 1. Antoine Lavoisier.

The Law of Conservation of Mass was proposed by Antoine Lavoisier in 1789. Lavoisier was a French chemist who is considered to be the father of modern chemistry. He conducted a series of experiments that showed that mass is neither created nor destroyed in chemical reactions. In other words, the total mass of the reactants must equal the total mass of the products.

Lavoisier's discovery of the Law of Conservation of Mass was a major breakthrough in chemistry. It helped to disprove the phlogiston theory, which was a popular theory at the time that stated that fire was a substance called phlogiston that was released from materials during combustion. Lavoisier's experiments showed that fire was not a substance, but rather a chemical reaction in which oxygen was combined with other elements.

The Law of Conservation of Mass is one of the most fundamental laws of chemistry. It is used in many different areas of chemistry, including stoichiometry, thermodynamics, and kinetics. It is also used in other fields, such as physics and biology.