Iodine-125 has a half-life of 60.4 days and is used in radiation therapy to treat prostate cancer and brain tumors. If a patient ingests 10.0 g of 125I, how much will remain after 1.00 year?

The half-life of radon-222 is 3.8 days. How much of a 100 gram sample is left after 15.2 days?

A fabric remnant from a burial site has a 14C/12C ratio of 0.546 of the original value. How old is the fabric?

A radioactive sample has a mass of 500 grams. How much remains after two half-lives?

What types of radiation (electromagnetic radiation and/or high-energy particle) are produced in the radioactive decay of lutetium-177?

lodine-125 is a radioactive isotope commonly used in medicine. It has a half-life of 59.5 days. A sample contained 2.00 kg lodine-125 when it was made. How old is the sample when it contains 0.0625 kg Iodine- 125 (in days)?

Phosphorus-32 (3215P) decays by beta emission and it has a half-life of 14.3 days. Determine the activity (or decay rate) of 3215P in a 1.0-g sample of the compound K2H32PO4 (potassium hydrogen phosphate labeled with 32P; molar mass = 175.2 g/mol) and express the activity in curies (Ci)        (Avogadro’s number, No = 6.022 x 1023/mol;  1Ci = 3.7 x 1010 cps = counts per second)          (A) 5.2 x 104 Ci             (B) 2.9 x 105 Ci          (C) 1.7 x 106 Ci          (D) 1.6 x 103 Ci

Iodine-125 is a radioactive isotope commonly used in medicine. It has a half-life of 59.5 days. Suppose at the start of Day 1 you store 3.77 kg of Iodine-125 in a cabinet and do not use it. After 119 days, how much Iodine-125 will you have (in kg)?