Atom A has a mass number 238 and atomic number 92 and atom B has mass number 235 and atomic number 92. (i) How many protons, atoms A and B have? (ii) How many neutrons, atoms A and B have? (iii) Are atoms A and B isotopes of the same element? How?

(i) Protons in atoms A and B = 92
(ii) Neutrons in atom A and B = 146 and 143
(iii) Yes, atoms A and B are isotopes of the same element.