Neutrons and protons are in the nucleus
electrons are on shells which orbit the nucleus
The law of conservation of mass states that mass or matter cannot be created or destroyed, only transferred or recombined.
For chemical equations, this law means that each element must be accounted for equally both for reactants and products. So the same numbers of each atom must match on each side, hence the necessity for balancing the chemical equation accurately. This created a field of chemistry called Stoichiometry, which accounts for the conservation of matter throughout chemical reactions and processes.
Answer: 66
Explanation: To find the mass number you would have to add the number of protons and the number of neutrons.
