A monitoring system records data for a nucleus during two successive emissions.
| Stage | Mass number | Atomic number |
|---|---|---|
| Before the first emission | 58 | 29 |
| After the first emission | 58 | 28 |
| After the second emission | 58 | 28 |
During the second emission, the energy of the nucleus decreases.
A technician concludes that both emissions are gamma radiation because the mass number does not change.
Evaluate the technician's conclusion.