Bromine Isotopes

Bromine Isotopes

The concept of isotopes is one of the most vital one in the field of chemistry. In this article, we shall know which are the stable and unstable bromine isotopes in detail.
Bromine is an important chemical element and has a symbol Br. The chemical properties of bromine are quite unique and distinguished as compared to those of other elements. Here are some of the notable bromine properties which you should know:
  • The atomic number of bromine is 35
  • Elemental bromine is toxic as well as corrosive; whereas free bromine is crystalline in nature and does not have a color
  • It is more reactive than iodine, but less reactive than chlorine
  • It is highly soluble in acetic acid and carbon disulphide and is known to have intense and strong bleaching action with several other elements
  • It has just 2 stable isotopes whereas there are around 23 radioisotopes
Though the main focus of this article is on its isotopes,we can understand that better only after we are clear with the meaning of the term 'isotopes'.


The concept of isotopes was first suggested by Frederick Soddy way back in 1913 after studying radioactive decay chains thoroughly. Isotopes are defined as the variants of atoms of an elements which have unequal number of neutrons in them. If a particular element has two isotopes, than the mass number, or the number of nucleons in them, will not be the same. Now, you may want to know what exactly is the meaning of 'nucleons'. Nucleons is the sum of total number of protons and total number of neutrons of the element.

So, Nucleons = (Number of Protons) + (Number of neutrons). If an element has isotopes which are radioactive in nature, then they are called radioisotopes. Tin is the element which has maximum number of stable isotopes which is 10. 79Br and 81Br are the two stable isotopes of bromine.

Isotopes of Bromine

Bromine isotopes Br-79 and Br-81 have great application sin the field of medicine. While Br-81 has been useful for diagnostic purposes, Br-79 is helpful in radiotherapy after getting decayed into the radioisotope Br-77. Another known fact about bromine isotopes is that most of them are results of fission.

Nuclide SymbolNeutron NumberIsotopic MassHalf Life
66Br31Not knownNot known
67Br3266.96Not known
68Br3367.95<1.2 micro sec
69Br3468.95<24 nano sec
70Br3569.9479.1 milli sec
71Br3670.9321.4 sec
72Br3771.9378.6 seconds
73Br383.472.9 min
74Br3973.9225.4 min
75Br4074.9296.7 min
76Br4175.9216.2 hours
77Br4276.9257.036 hours
78Br4377.926.46 min
80Br4579.9117.68 min
82Br4781.9135.28 hours
83Br4882.912.40 hours
84Br4983.9131.80 min
85Br5084.912.90 min
86Br5185.9155.1 sec
87Br5286.9255.65 sec
88Br5387.9216.29 sec
89Br5488.924.40 sec
90Br5589.931.91 sec
91Br5690.93541 milli sec
92Br5791.930.34 sec
93Br5892.94102 milli sec
94Br5993.9470 milli sec
95Br6094.95>300 nanosec
96Br6195.95>300 nanosec
97Br6296.96>300 nanosec

Here are some more bromine isotopes and their half-life that may interest you.

Some More
Nuclide SymbolHalf Life
70mBr2.2 seconds
72mBr10.6 seconds
74mBr46 minutes
76mBr1.31 seconds
77mBr4.28 minutes
78mBr119.2 microseconds
79mBr4.86 seconds
80mBr4.42 hours
81mBr34.6 microseconds
82mBr6.13 minutes
83mBr700 nanoseconds
84m1Br6.0 minutes
84m2Br<140 nanoseconds
88mBr5.4 microseconds

In general, the concept of isotopes is important to understand principles and fundamentals of advanced chemistry. So, my suggestion to those planning a career in chemistry would be to get your basics right so that you can go deep into this interesting subject and understand it thoroughly.