▁have ▁nuclear ▁spin ▁ 3 / 2 − ▁and ▁thus ▁may ▁be ▁used ▁for ▁nuclear ▁magnetic ▁reson ance , ▁although ▁ 8 1 Br ▁is ▁more ▁fav ou rable . ▁The ▁relatively ▁ 1 : 1 ▁distribution ▁of ▁the ▁two ▁is ot op es ▁in ▁nature ▁is ▁helpful ▁in ▁identification ▁of ▁b rom ine ▁containing ▁comp ounds ▁using ▁mass ▁spect ro sc opy . ▁Other ▁b rom ine ▁is ot op es ▁are ▁all ▁radio active , ▁with ▁half - l ives ▁too ▁short ▁to ▁occur ▁in ▁nature . ▁Of ▁these , ▁the ▁most ▁important ▁are ▁ 8 0 Br ▁( t 1 / 2 ▁= ▁ 1 7 . 7   min ), ▁ 8 0 m Br ▁( t 1 / 2 ▁= ▁ 4 . 4 2 1   h ), ▁and ▁ 8 2 Br ▁( t 1 / 2 ▁= ▁ 3 5 . 2 8   h ), ▁which ▁may ▁be ▁produced ▁from ▁the ▁neut ron ▁activation ▁of ▁natural ▁b rom ine . ▁The ▁most ▁stable ▁b rom ine ▁radio is ot ope ▁is ▁ 7 7 Br ▁( t 1 / 2 ▁= ▁ 5 7 . 0 4   h ). ▁The ▁primary ▁decay ▁mode ▁of ▁is ot op es ▁l ighter ▁than ▁ 7 9 Br ▁is ▁electron ▁capture ▁to ▁is ot op es ▁of ▁selenium ; ▁that ▁of ▁is ot op es ▁heav ier ▁than ▁ 8 1 Br ▁is ▁beta ▁decay ▁to ▁is ot op es ▁of ▁k rypt on ; ▁and