Answer:
I don't know the ans please search on the Google you will get
And don't forget to mark me as brainlest please guys and follow me back please please please please please
And I will help you tooooooooooooooooo and follow u back if you follow me
Proton plus neutron is the correct answer. Protons and neutrons have a mass of 1 and electrons have a mass of 0. So in order to find the mass of an atom you need to add the number of protons and the number of neutrons.