atomic mass is determined by the number of protons and neutrons
atomic_nucleus is microscopic_object. equivalent is atomic_mass. hydrogen_atoms has one_proton_and_one_electron hydrogen has atomic_number_of_one neutron_bomb is atomic_weapon. neutrons has about_as_much_mass_as_protons atoms has mass protons is component_of_atoms. atomic_number is number. atomic_mass is mass.