a. The dosage of technetium-99m for a lung scan is 20.

Solution 28QPStep 1 of 2a.Here, we have to find the millicuries of technetium-99m are needed for a 50.0kg patient.Here, the main unit is Ci.Curie(Ci) is the original unit of activity.And it is defined as the number of disintegrations that occur in 1s for 1 g of radium.The given:The recommended dosage of technetium- 99m for lung scan is 20 µCi/kg of body mass.From the given it is clearly states that 1 kg body mass is equal to 20 µCi.Let’s write the conversion factors:1 Kg = 20 µCiSo, the conversion factors are and For 50.0 kg body mass:50.0 kg = 1,000 µCi.Let’s convert the microcuries into millicuries1 millicurie = 1,000 µCi.So, the conversion factors are and For 1,000 µCi. 1,000 µCi = 1 millicurie.Therefore, 1 millicurie of technetium-99m are needed for a 50.0kg patient.______________________________________________________________________________