\({ }^{131} I\) is an isotope of Iodine that \(\beta\) decays to an isotope of Xenon with a half-life of 8…
\({ }^{131} I\) is an isotope of Iodine that \(\beta\) decays to an isotope of Xenon with a half-life of 8 days . A small amount of a serum labelled with \({ }^{131} I\) is injected into the blood of a person. The activity of the amount of \({ }^{131} I\) injected was \(2.4 \times 10^5\) Becquerel \((\mathrm{Bq})\). It is known that the injected serum will get distributed uniformly in the blood stream in less than half an hour. After 11.5 hours, \(2.5 \mathrm{ml}\) of blood is drawn from the person's body, and gives an activity of \(115 \mathrm{~Bq}\). The total volume of blood in the person's body, in litres is approximately (you may use $e^x \approx 1+x$ for \(|x|<<1\) and \(\ln 2=0.7\).