Three sealed laboratory sources individually emit only one type of radiation: (i) an α source, (ii) a β− source, and (iii) a γ source. None of the sources emits any other particles. A student wants to compare the intrinsic properties of the emitted particles and evaluate appropriate safety measures for routine handling of each source in open air.
(1) Rank the three emitted particles by their rest mass, from greatest to least, and justify your ranking using nuclear‐scale reasoning.
(2) Rank the three emitted particles by their electric charge, clearly indicating the sign and relative magnitude of each charge. Justify your ordering.
(3) Rank the three radiations by their ability to travel through ordinary matter (penetrating power) and, correspondingly, by the typical ionization density they produce along their paths. Provide a qualitative explanation for each position in your ranking.
(4) For each source, recommend the minimal common laboratory shielding material (for example, sheet of paper, a few millimetres of plastic, or several millimetres of lead) that would reduce the external radiation hazard to negligible levels. Support each recommendation by referring to the properties you discussed earlier.