atom A has a mass number 238 and atomic number 92 and atom B has a mass number 235 and atomic number 92. how many protons, atoms A and B have? how many neutrons, atoms A and B have? are atoms A and B isotopes of the same element? how? Share with your friends Share 2 Geetha answered this Atom A has mass number as 238 and atomic number 92.So number of protons = 92. Number of neutrons = 238-92=146Atom B has mass number as 235 and atomic number 92.So number of protons = 92. Number of neutrons = 235-92=143Number of protons of A and B =92Number of neutrons of A and B=146,143As the atomic number is same, they are isotopes. 3 View Full Answer Dimple answered this protons of atom A and B =92 as atomic no. = no. of protons 0 Dimple answered this neutrons of A =238-92= 146 -2 Dimple answered this neutrons of B=235-92= 143 0 Dimple answered this and yes,dey r d isotopes of d same element as isotope have same atomic no. but diff. mass nos -1