Question

chemical equations are balanced when what quantity or quantities are the same? drag an oval over each statement that applies.
the sum of the subscripts of all substances involved.
the sum of masses of all substances involved.
the number of molecules of each kind.
the number of atoms of each kind.

Explanation:

A balanced chemical equation adheres to the law of conservation of mass, which means the total mass of reactants equals the total mass of products. Additionally, the core requirement for balancing is that the number of each type of atom is identical on both sides of the equation. Subscripts represent fixed chemical formulas and do not change during balancing, so their sum is not equalized. The number of molecules of each kind can differ (adjusted via coefficients) as long as atom counts are balanced.

Answer:

• The sum of masses of all substances involved.
• The number of atoms of each kind.