Law of conservation of mass

In Chemistry and Physics, the law of conservation of mass states that matter cannot be created or destroyed in ordinary chemical reactions—the total mass of reactants equals the total mass of products. Formalized during the 18th century, this principle became foundational to understanding how substances transform.

The law held unquestioned until Einstein revealed its deeper truth: mass and energy are interchangeable through the equation E=mc². Tiny amounts of mass convert to enormous energy in nuclear reactions, meaning the "law" must be refined as conservation of mass-energy. In everyday chemical processes, however, the effect is imperceptible, and mass remains effectively conserved.

This principle underpins Stoichiometry, the art of calculating exact quantities in reactions. It's essential to Biochemistry, industrial manufacturing, and environmental accounting—tracking where atoms go matters profoundly when considering resource sustainability.

The law demonstrates how logical reasoning about the natural world can persist for centuries, then evolve when we glimpse deeper reality. Wonder and precision dance together here.

Related

Stoichiometry, Chemical equation, Antoine Lavoisier, Thermodynamics, Mass-energy equivalence, Nuclear physics