Through mass spectrometry, we can define 4 different isotopes of the BrCl molecule:
⁸¹Br³⁷Cl, ⁸¹Br³⁵Cl, ⁷⁹Br³⁷Cl, ⁷⁹Br³⁵Cl
Masses of the different individual isotopes:
³⁷Cl=36.966
³⁵Cl=34.968
⁸¹Br=80.916
⁷⁹Br=78.918
Masses of 4 different isotopes of the BrCl molecule:
⁸¹Br³⁷Cl=80.916+36.966=117.882
⁸¹Br³⁵Cl=80.916+34.968=115.884
⁷⁹Br³⁷Cl=78.918+36.966=115.884
⁷⁹Br³⁵Cl=78.918+34.968=113.886