Final answer:
The true statement about the atoms in chemical reactions is that the number of atoms remains the same while their arrangement changes. This adheres to the law of conservation of mass, with the total mass of products equating to that of the reactants in a closed system.
Step-by-step explanation:
The correct answer to the question 'Which of the following is true about the atoms of the reactants and products in a chemical reaction?' is B) The number of atoms is the same in both, but their arrangement will be different. This is supported by the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, a balanced chemical equation must have the same number of atoms of each element on the reactant and product sides. Atoms are never lost or gain additional atoms; they simply get reorganized into different molecules or compounds.
Chemical reactions involve breaking bonds in the reactants and forming new bonds to create the products. While the number of atoms remains constant, their arrangement in space and the bonds between them change, leading to different substances with different properties. The conservation of mass ensures that the masses of the reactants and products in a closed system are equal.