Cesium-137 decay is a source of which radiation?

Cesium-137 decay is a source of which radiation?

• A. Alpha radiation
• B. Gamma radiation
• C. Neutron radiation
• D. Beta radiation

Answer: (D)

Cesium-137 decays by beta minus emission to a metastable state of barium-137. The beta particle is the radiation released during this decay step. After the beta emission, the daughter nucleus Ba-137m promptly emits a gamma ray as it relaxes to its ground state. That means the decay process itself produces beta radiation, while gamma radiation appears as a byproduct of the daughter’s transition. Alpha and neutron radiation aren’t part of this decay path, so they’re not produced by cesium-137. The gamma photons are still important for shielding considerations because they’re highly penetrating, but the primary radiative output of the decay event is beta radiation.

Cesium-137 decays by beta minus emission to a metastable state of barium-137. The beta particle is the radiation released during this decay step. After the beta emission, the daughter nucleus Ba-137m promptly emits a gamma ray as it relaxes to its ground state. That means the decay process itself produces beta radiation, while gamma radiation appears as a byproduct of the daughter’s transition. Alpha and neutron radiation aren’t part of this decay path, so they’re not produced by cesium-137. The gamma photons are still important for shielding considerations because they’re highly penetrating, but the primary radiative output of the decay event is beta radiation.