What is the Decay Rate (k), if the Half Life of a radioactive substance is 13.8 days? (ans. rounded to six decimal places.)

Radioactive vanadium-48 decays with a half-life of 16.0 days. a. What is the value of k in s? k = b. A sample contains 84.0 mg *°V. How many decay events will be produced in the first second? Assume the atomic mass of **V is 48.0 u. decays/s c. A chemist obtains a fresh sample of 48 V and measures its radioactivity. She then determines that to do an experiment, the radioactivity cannot fall below 25% of the initial measured value. How long does she have to do the experiment? days

The half-life of 14C is 5730 years, and the current decay rate in living organisms is 14.3 disintegrations per minute per gram of carbon (d.p.m./g C). What is the age (in years BP) of an artifact found to have a decay rate of 4.75 d.p.m/g C in 2013? IMPORTANT: When entering your answer: • Enter the number only (no units) • Do not leave any spaces • Report your number to the tens column (regardless of the significant figures) Correctly round your answer to the tens column (margin of allowed error is only ± 10, so always use un-rounded numbers in your calculations) Examples: 12340 or 5670 (include the zero in the units column, Canvas will add a comma for you)

The half-lives of different radioisotopes are given in the table. Half-life (min) Radioisotope argon-44 lead-196 time: potassium-44 indium-117 How long would it take, in minutes, for the amount of argon-44 to decrease from 64.0 mg to 8.00 mg? ADI 12 37 22 43 NOV 1 C min C 3:37 1 ()))

A sample of wood from an Egyptian mummy case gives a count of 8.4 cpm/gC (counts per minute per gram of carbon). How old is the wood? (The initial decay rate of is 15.3 cpm/gC, and its half-life is 5730 years.)

A bottle of wine, which was analyzed for its tritium (3H) content, was found to contain 13.35% of the 3H that was originally present when the wine was bottled. How old is the bottle of wine (in years)? (The half-life of 3H is 12.5 yr.) 4 sig figs if possible please

c. Plutonium-238 is used in spacecraft to provide heat to power generators. One of thesegenerators contained 765 g of plutonium-238 when it was manufactured. Given that thehalf-life of plutonium-238 is 87.7 years, calculate the mass of plutonium-238 remainingafter 350.0 years.