What does the principle of Conservation of Mass state?

The principle of Conservation of Mass states that in a closed system, the total mass of the reactants before a chemical reaction occurs is equal to the total mass of the products after the reaction has taken place. This means that during a chemical reaction, atoms are neither created nor destroyed; they are simply rearranged to form new substances.

This principle is fundamental in chemistry as it underpins balanced chemical equations, where the number of atoms of each element remains constant before and after the reaction. Understanding Conservation of Mass allows chemists to predict the outcomes of reactions and determine how much reactant is needed to produce a desired amount of product.

In contrast, other options address misconceptions: creating or destroying mass does not occur in any chemical reaction, and while mass does relate to physical changes, this statement fails to encompass its significance in chemical transformations. The correct understanding of mass conservation is vital for grasping the nature of reactions and stoichiometry in chemistry.