A patient is injected with 7.58 μCi7.58 μCi of radioactive iodine‑131 that has a half‑life of 8.028.02 days. Assuming that 90%90% of the iodine ultimately finds its way to the thyroid, what decay rate ?R do you expect to find in the thyroid after 2626 days?

^3H decays to ^3He (Helium) with a half life of 12.32 years. If you start off with 1,000,000 atoms of ^3H how many years will it take for the number of ^3H atoms to reach 125,000?

The natural radioisotope, radium-226 (226Rn), undergoes a radioactive decay where it emits an alpha particle to become radon-222 (222Rn) which has a half-life of 3.82 days. Will a sample of 222Rn be at less than one fifth (1/5) of its original strength after a period of 5 days? Explain.

Krypton-81m is used for lung ventilation studies. Its half-life is 13 ss. How long does it take the activity of this isotope to reach one-quarter of its original value?

The currently accepted value for the half-life of radiocarbon is 5,730 years. Based on that information, which of the following conclusions is correct. 1. In 2,865 years, the entire original amount of carbon-14 in the sample will be gone. 2. In 11,460 years, the entire sample will be another element. 3. In 5,730 years, half of the original sample of carbon will be gone. 4. In 5,730 years, half of the original amount of carbon-14 in the sample will be gone.

Strontium-89 is a beta emitter with a half-life of 50.6 days that is used in bone cancer treatment. How many days will it take for a 69.6 mg sample of Sr-89 to decay to 0.148 mg?​ (Assume no excretion of the nuclide from the body).

The half-life of Strontium-85 is 65 days. How much of a 80. mg sample is left after 260 days? mg

Three radioisotopes X, Y, and Z have half-lives of 1, 2 and 5 years respectively. Each of the three radioisotopes has the same activity now in July 2020. Which radioisotope will be hotter (meaning it will have more activity remaining) if you were to examine them at different times in the future, specifically in July 2023 for X, July 2024 for Y, and July 2040 for Z? Provide a full explanation of your reasoning. O Y because 2 half-lives will have passed by July 2024. OX because July 2023 is sooner than July 2024 or July 2040. OX because 3 half-lives will have passed by July 2023. O Z because July 2023 is sooner than July 2024 or July 2040. Z because July 2040 is later than July 2023 and July 2024. O Y because July 2023 is sooner than July 2024 or July 2040. O Z because 4 half-lives will have passed by July 2040.