Assume that a hypothetical radioactive isotope has a half-life of 15 years. A 100.0-mCi sample of...
1. The half-life of an isotope of phosphorus is 14.2 days. If a sample contains 3.96e16 such nuclei, determine its activity.? 2. A 234-mCi sample of a radioactive isotope is purchased by a medical supply house. If the sample has a half-life of 17.4 days, how long will it keep before its activity is reduced to 28.9 mCi?
A freshly prepared sample of a radioactive isotope has an activity of 27.5 mCi. After 2.60 hours, the activity is 21.0 mCi. (a) Determine the half-life of the isotope. (h) (b) How many nuclei of the isotope were contained in the freshly prepared sample? (nuclei) (c) After how much time will the activity be 1.40 mCi? (h)
A freshly prepared sample of a certain radioactive isotope has an activity of 10.0 mCi. After 3.80 h, the activity is 8.30 mCi. (a) Find the decay constant and half-life of the isotope. (b) How many atoms of the isotope were contained in the freshly prepared sample? (c) What is the sample's activity 30 h after it is prepared?
If a container of radioactive isotope has a half-life of 10 years, how many years will it take for there to only be 25% of the isotope remaining in the container.
Part A: Tritium is a radioactive isotope of the element hydrogen. Tritium has a half-life of 12.5 years. How many years would it take until only 3.22% of a sample remain? Answer should be in years. Part B: Radioactive Carbon-11 has a half life of only 20.3 minutes and an atomic mass number of 11 u. Calculate the activity of 3.58 g of Carbon-11. Answer should be in Bq.
14C is a radioactive isotope with a half life of 5.73x10^3 years. Radioactive decay is first order process and the amount of 14C present in an object can be used to determine its age. How long does it take for for 90 % of the 14C in a sample to decompose?
If a radioactive isotope has half-life h, then the number of atoms in a sample is given by a(t)=a-2-/h where ao gives the number of atoms in the sample at time 0. The radio active decay of carbon-14 leads to clever way of determining the age of fossils and remnants of plants and animals. When an organism dies, the radioactive carbon- 14 in it decays, with half of it gone in 5,730 years. a. Suppose a mummified cat has a...
V Question 5 3.03 pts Suppose a radioactive isotope has a half-life t% = 99.1 hr. How long will it take for a sample of the isotope to decay to 3.0% of its original activity? a. 218 hr b. 0.0354hr c. 348 yr d. 297 hr e. 501 hr O a Ob Ос Question 6 3.03 pts A radioactive isotope has a half-life, t% = 27.3 yr How long will it take for a 3.27 mCi sample of this isotope...
8. Fermium-253 has a half-life of 0.334 seconds. A radioactive sample is considered to be completely decayed after 10 half-lives. How much time will elapse for this sample to be considered gone? 9. 100.0 grams of an isotope with a half-life of 36.0 hours is present initially. How ma time will have elapsed when 5.00 grams remains? 131 (half-life = 8.040 days) to decay to 10. How long will it take for a 40.0 gram sample of 1-131 (half-life =...
A 0.0116-g sample of a radioactive isotope with a half life of 1.3x109 years decays at the rate of 2.9x104 disintegrations per minute. Calculate the molar mass of the isotope. Enter your answer in scientific notation. (g/mol)