Atoms that have different numbers of neutrons than protons and electrons are called isotopes.
The correct answer should be letter choice C) There is an equal number of each type of atom on the reactant and product side. Its C) because if its trying to conserve mass, than that means save or be equally balanced so it should be even for both sides.
The answer is 71.5g of potassium sulfate
Answer: 1.324L
Explanation: use Boyles law, sorry so late!