What is the equivalent of 127 mCi in GBq?

To convert millicuries (mCi) to gigabecquerels (GBq), it is essential to understand the relationship between these two units of radioactivity. The conversion factor between curies (Ci) and becquerels (Bq) is that 1 Ci is equivalent to 37 billion Bq (37 GBq). Consequently, 1 mCi is equivalent to 37000 Bq (or 0.037 GBq) since 1 mCi is 1/1000 of a Ci.

To convert 127 mCi to GBq, you can use the conversion:

[ 127 \text{ mCi} \times 0.037 \text{ GBq/mCi} = 4.699 \text{ GBq} ]

When rounding this result, you find that it is approximately 4.70 GBq. This is why the correct choice is the one that corresponds to 4.70 GBq. The solution demonstrates the direct application of the conversion factor and shows how to achieve the calculation step-by-step, illustrating the fundamental principles of unit conversion in nuclear medicine.