What principle states that matter cannot be created or destroyed, only converted between forms?

The principle that states that matter cannot be created or destroyed, only converted between forms, is rooted in the concept of conservation of matter. This means that during any chemical reaction or physical change, the total mass of the reactants must equal the total mass of the products. This foundational idea is essential in both chemistry and physics, as it helps us understand that while matter may change state—to solids, liquids, or gases—it remains constant in total quantity.

In contrast, while the Law of Conservation of Energy and the First Law of Thermodynamics are related concepts that address energy transformations and the idea that energy cannot be created or destroyed (only transformed), they do not explicitly cover the conservation of matter in the same way. The Second Law of Thermodynamics deals with the direction of energy transfers and the concept of entropy, which is separate from the matter conservation principle. Thus, the answer accurately reflects the specific definition regarding the conservation of matter.