Answer
The recommended dosage of iodine-131 for that person is: $294 µCi$.
Work Step by Step
1. Identify the objective.
- Calculate the amount of microcuries of iodine-131 in a dosage for a 70.0-kg person.
2. Find the conversion factor.
- There are necessary $4.20 µCi$ of iodine-131 for each kg of body mass: $\frac{4.20 µCi}{1 kg}$ and $\frac{1kg}{4.20 µCi}$
3. Calculate the value for the dosage:
$70.0 kg \times \frac{4.20 µCi}{1kg} = 294 µCi$
4. Adjust the value to the correct number of significant figures:
- Data with lowest SF's: $70.0 kg$ - 3 SF's.
Therefore, the result must have 3 SF's: $294 µCi$
