What scientific principle states that matter cannot be created or destroyed?

The correct answer highlights the principle that in any chemical reaction or physical process, the total mass of the substances involved remains constant over time. This means that matter can change forms or combine in reactions, but the total amount of matter in an isolated system remains unchanged.

This law underpins much of chemistry and physics, forming a foundational concept that has been established through extensive experimentation and observation. For instance, in a chemical reaction, the mass of the reactants will always equal the mass of the products. This principle is essential for understanding chemical equations and balancing reactions, as it ensures that scientists account for all atoms involved before and after the reaction takes place.

Understanding this principle is crucial for various applications in both academic and real-world contexts, such as in laboratory experiments, industrial processes, and environmental science, where mass changes must be tracked accurately.