A hospital receives a shipment of a radiopharmaceutical containing

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

A hospital receives a shipment of a radiopharmaceutical containing 131I^{131}\text{I}, whose half-life is 8.04 days8.04\,\text{days}. The initial activity of the shipment is 50.0 MBq50.0\,\text{MBq}. For patient-safety regulations, the activity must fall below 1.00 MBq1.00\,\text{MBq} before the remaining material can be discarded as non-radioactive waste. (1) Calculate the numerical value of the decay constant λ\lambda for 131I^{131}\text{I}, including proper units. (2) Determine the elapsed time required for the activity to decrease from 50.0 MBq50.0\,\text{MBq} to the 1.00 MBq1.00\,\text{MBq} threshold. (3) Express your result from part (b) in the form “xx days yy hours,” where 0≤y<240\le y<24. Briefly interpret what this time interval means in the context of the hospital’s disposal schedule.

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