A vile contains radioactive iodine -131 with inactivity of 2.0 mCi/mL. If a thyroid test requires 3.6 mCi in an “atomic cocktail,” how many millimeters are used to prepare the iodine -131 solution?

Question

Express the volume to two significant figures and include the appropriate units.

Answer 1

3.6 mCi x 1 ml / 2.0 mCi = 1.8 ml needed