In the process of balancing chemical equations, which numbers must remain unchanged?

• A. The total number of molecules
• B. The subscripts in chemical formulas
• C. The number of atoms on each side
• D. The coefficients in front of compounds

Answer: (B)

Verified step by step guidance

1. Understand that in balancing chemical equations, the goal is to ensure the law of conservation of mass is obeyed, meaning the number of atoms of each element must be the same on both sides of the equation.
2. Recognize that coefficients (the numbers placed before compounds) can be changed to balance the equation, as they represent the number of molecules or moles of a substance.
3. Know that subscripts (the small numbers within chemical formulas) represent the fixed number of atoms in a molecule and must not be changed because altering them changes the identity of the compound.
4. Realize that the total number of molecules can change as coefficients are adjusted to balance atoms, so this number does not have to remain constant.
5. Conclude that the numbers that must remain unchanged during balancing are the subscripts in chemical formulas, as they define the chemical identity of the substances involved.