Write the balanced nuclear equation representing the beta and gamma radiation emission of the isotope cesium-137.

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jgoulden eNotes educator| Certified Educator

Cesium-137 beta-decays to Barium-137m (a metastable state of Barium-137), which then emits one or more gamma rays when it decays to the ground state. Since the atomic number has increased from 55 (Cesium) to 56 (Barium), conservation of charge demands that a negative electron (as opposed to a positive electron or positron) be ejected during the decay process. The equation describing this process can be written as

Cs-137 + negative electron = Ba-137m + gamma