Which of the following gives an atom's mass number? Question 1 options: a. number of neutrons b. number of neutrons + number of protons c. number of protons + number of electrons d. number of protons + number of neutrons + number of electrons Save

I would say the answer is B ...

The atom's mass number is the "number of neutrons and number of protons (option B) in an atomic nucleus. It might determine the atomic mass os atoms. Because neutrons and protons are baryons, the mass number A is identical to mass number B as of the nucleus, atom or iron.