Describe alpha, beta positive, beta negative and gamma radiation, including the properties of penetrating ability, charge, mass and ionisation ability.

A research laboratory uses three sealed sources to calibrate radiation detectors. Each source emits a different type of radiation. The table below shows the detector readings when different shielding materials are placed between each source and the detector. Compare the penetrating ability of the three types of radiation and relate each to the properties of charge and mass.

A radioactive nucleus undergoes decay and emits a particle that has a charge of $+2e$, a mass number of 4, and is stopped by a sheet of paper. Which type of radiation is being emitted?

A medical physics laboratory is testing the shielding requirements for different radioactive isotopes used in diagnostic imaging and cancer therapy. The table below shows experimental data collected when radiation from four different sources was directed at various shielding materials of increasing thickness. Refer to the experimental data above. Justify which radiation type (A, B, C or D) is most likely gamma radiation, and explain why a different radiation type would require significantly less shielding mass despite having higher ionisation ability.