In order to solve the question, one must understand that:
- An atom is made up of neutrons which has no charge, negatively charged electrons, and positively charged protons.
- The mass number of an atom is the number of protons plus neutrons of the atom. It is also the atomic mass number of the atom.
- A neutral atom has an equal number of positive (proton) and negative (electron) charges.
Hence, in order to create a neutral atom with a mass number of 3, the proton and neutron number must add up to 3 while the proton and electron number must be equal.
More on mass number can be found here: https://brainly.com/question/1371394
