Yttrium-90 is a beta-emitting radionuclide used in targeted radiation therapy for cancer treatment. It has a half-life of 64.0 hours64.0\text{ hours}64.0 hours. What is the total activity of a 4.8 μg4.8\text{ }\mu\text{g}4.8 μg sample of yttrium-90?
(Atomic mass of 90Y=90.0 g mol−1^{90}\text{Y} = 90.0\text{ g mol}^{-1}90Y=90.0 g mol−1, NA=6.02×1023 mol−1N_{\text{A}} = 6.02 \times 10^{23}\text{ mol}^{-1}NA=6.02×1023 mol−1)
3.5×1014 Bq3.5 \times 10^{14}\text{ Bq}3.5×1014 Bq
9.7×1016 Bq9.7 \times 10^{16}\text{ Bq}9.7×1016 Bq
9.7×1010 Bq9.7 \times 10^{10}\text{ Bq}9.7×1010 Bq
1.4×1011 Bq1.4 \times 10^{11}\text{ Bq}1.4×1011 Bq
