Bombarding Br-81 with gamma rays gives a radioactive nuclide and a neutron. What is the radionuclide?
Comparing the charges and atomic masses on the both sides of the nuclear reaction, we observe that the daughter nuclide has
It is therefore, clear that the radioactive nuclide is an isotope of Bromine with mass number one less than the parent.
Therefore, the daughter is
It is known that
#"_35^80text(Br)-> beta^-# #+ "_36^80text(Kr)# #"_35^80text(Br)-> beta^+# #+"_34^80text(Se)#