35. If the half-life of a radioactive isotope is 200 years, and a specimen contained 5 grams of parent isotope and 15 grams of daughter product, then how many half-lives have elapsed.

Q: How many half‑lives of the unknown radioactive substance have occurred?

A: As we know that decay of radioactive substance follows first order kinetics

Q: The half life of an isotope is 43 seconds.  How long does it take 100.00 g of that isotope to decay…

A: Given that  Initially weight of isotope sample = 100.0 gm initially number of atoms of isotope No=…

Q: A 116.8 ng sample of an unknown radioactive substance was placed in storage and its mass measured…

A: Given- Initial amount=116.8ng Final amount=14.60ng Time=47days

Q: A 739.7 ng sample of an unknown radioactive substance was placed in storage and its mass measured…

A:

Q: Sulfur-38 Original amount: 5.0 g Amount left: c Total time: 8.61 h Half-life: 2.87 h Number of…

A:

Q: A moon rock collected by a U.S. Apollo mission is estimated to be 3.70 billion years old by…

A: Since this is a first order decay The rate constant with half life is given by…

Q: The Cs-131 nuclide has a half-life of 30 years. After 120 years, 5.3 g remain. What is the original…

A: The objective of this question is to find the original mass of the Cs-131 sample given its half-life…

Q: You are studying a sample of granite that is about 2.1 billion years old. You know it contains some…

A: Here granite containing uranium -235 is formed 2.1 billion years old. We have to determine the…

Q: The Cs-131 nuclide has a half-life of 30 years. After 120 years, 4.5 g remain. What is the original…

A:

Q: The half-life of Polonium-218 is 3.00 minutes.  How many half-lives pass after 18.0 minutes ?  The…

A: Concept - Radioactive decays are first order reactions. So we use the formula, Nt = No(1/2)n, where…

Q: Bi-191 has a half-life of only about 12 seconds. A large radioactive sample contains only 4.1 x 109…

A: Half life of Bi-191 = 12 sNumber of atoms of Bi-191 = 4.1 × 109 atomsNumber of moles of Bi-191 = ?…

Q: The half-life of Po-218 is 3.05 minutes. How many minutes does it take for a sample of Po-218 to…

A: Given: Half-life of Po-218 = 3.05 minutes. And the final amount of Po-218 isotope remaining = 2.35 %…

Q: Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 55 mg of…

A: To find alpha emissions:

Q: A 4.0 g sample of Ra-226 decays to 1.0 g. If the half-life of Ra-226 is 1620 years, how much time…

A: Given initial concentration of Ra-226 = [Ra-226]0 = 4.0 g  Final concentration = [Ra-226] = 1.0 g…

Q: The half life of radium 226 is 1602 years. If you have 500 grams of radium today how many grams…

A:

Q: The half-life of tritium is 12.32 yrs.If 49.1 mg of tritium remains of a sample with an initial mass…

A: The question is based on the concept of chemical kinetics. we have to calculate how much time has…

Q: An old wooden bowl unearthed in an archeological dig is found to have one‑fourth of the amount of…

A:

Q: The half–life of a radioactive material is 7.04 days. Assuming you start with a 1.45 mg sample, how…

A: Given , Half life = 7.04 days Time , t = 16 days Initial Weight of sample = 1.45 mg

Q: Can the half-life of a given isotope be manipulated or changed to suit human needs?

A: Answer

Q: If the half-life of a radioactive isotope is 32 days, how many half-lives must pass before a 3.0…

A: Radioactive decay follows the first-order kinetics. The half-life of the first-order reaction does…

Q: After 40.0 days, how much Ac-225 remains if the starting mass was 94.0 g? Ac-225 has a half life of…

A:

Q: Tc-99m is the most commonly used radioactive isotope in medicine. It is a gamma emitter and has a…

A: The half life of Tc-99 is six hours. There will be two half lives involved in twelve hours. The…

Q: 32p is a radioactive isotope with a half-life of 14.3 days. If you currently have 32.7 g of 32P, how…

A:

Q: 65 grams of a radioactive sample with a half-life of 6,000 years is allowed to decay for 75,000…

A:

Q: 1. A sample of einsteinium-252 decayed to 64.3% of its original mass after 300 days. a) What is the…

A: The rate law for the 1st order reaction is given by, k=1tln[A]0[A] where k is the rate constant, t…

Q: Carbon-14 has a half-life of 5715 years. It is used to determine the age of ancient objects. If a…

A:

Q: 1. How do nuclear reactions differ from ordinary chemical reactions?

A: Nuclear reactions:The reactions in which a nucleus or two nuclei of an atom and nucleons from the…

Q: The cesium-137 has a half life of 30 years after 90 years about 10g.remains. the original mass of…

A: