A radiation detector is used to measure the count rate from a radioactive sample. To identify the types of radiation emitted, various absorbers are placed between the source and the detector. The background count rate has already been subtracted from the measurements.
| Absorber material | Corrected count rate / s−1\text{s}^{-1}s−1 |
|---|---|
| None | 1200 |
| Paper | 350 |
| 0.5 cm Aluminum | 350 |
| Thick Lead | 20 |
Which types of radiation are being emitted by the source?
α\alphaα only
β\betaβ and γ\gammaγ
α\alphaα and γ\gammaγ
α\alphaα and β\betaβ
