image/svg+xml 94.6% max 0.5120 MeV β- 30.17 a 5.4% max 1.174 MeV β- 0.6617 11/2- 0 3/2+ 7/2+ 55Cs137 0.6617 MeV γ 85.1% 2.55m 56Ba137m 56Ba137 stable