Krypton-81 has a half-life of 2.29 × 105 years. A 750-mg sample of Krypton-81 undergoes electron capture. a. Write the reaction involving the electron capture of Krypton-81. b. How many half-lives would it take for the initial amount of Krypton-81 to become 2.9297 mg? Report your answer to the nearest whole number. c. Using the complete value of your answer in b, how many years would it take for the initial amount of Krypton- 81 to become 2.9297 mg?

Q: If 1 g of an isotope has a half life of 15 hr, the half life of 0.5 g sample is A. 15 hr B. 30 hr C.…

A: 1 g sample of an isotope has a half - life = 15 hr 0.5 g sample of an isotope has a half - life =?…

Q: 4. Tritium has a half-life of 12.5 years. If you had a sample of 8.00g of tritium today, how many…

A: Half life (T) = 12.5 years  Time (t) = 37.5 years  Original sample (No) = 8.00 grams  Undecayed…

Q: . A radioactive isotope has a half-life of 10 years. What fraction of the original mass will remain…

A: Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: The half-life of radium-222 is approximately 38 seconds. Step 3 of 3 :  How much of an 11 gram…

A: Half life (t1/2) = 38 s Initial amount (No) = 11 g Time (t) = 6 s Amount of radium-222 remains after…

Q: 25. Iodine-131 is a radioactive substance that can be used to treat certain thyroid conditions. It…

A: Q25) Given that: Half life = 8 days Mass of Iodine = 40 mg Remain after 4 half lives = ?

Q: 8. What mass of plutonium-240 will remain after 32,820 years if the initial sample contained 4.8 g…

A: No. of half lives = Total time/ half- lives n = 32820/6564 = 5 n = 5

Q: 1. Phosphorous - 32 has a half - life of 14 days.  After how many days will a 1000 mg sample decay…

A:

Q: Cs-134 has a half-life of 2.0 years. How much of a 2.50-g sample of this isotope will remain after…

A: Given :- half life of Cs-134 = 2.0 years                Initial amount of sample = 2.50-g  To…

Q: 9. A wood artifact is known to have decayed and only 55% of the original artifact remains. The age…

A: Since, you have asked multiple questions, we will solve the first question for you.  In Question-9…

Q: 1. A sample of radioactive iodine-131 atoms has a half-life of about 8 days. Suppose that 1 000 000…

A:

Q: An ancient wood sample is known to be 2500 years old. a. Knowing that the half-life of carbon is…

A:

Q: Calculate how long will it take for a sample of a radionuclide with a half-life of 31.3 days decay…

A: Given, Half life = 31.3 days  Time , t = ?

Q: Calculate the half-life of a radioisotope if it takes 144 years for a sample to decay to 12.5% of…

A: N = 0.125 No N/No = 0.125

Q: What

A: We will use relation between t1/2 and mass

Q: A certain isotope has a half-life of 2.00 days. How much of a 4.00g sample of this isotope will…

A: Since the decay reactions are first order reactions Hence we can say  1) Half life = ln(2) / K 2)…

Q: 3 Carbon-14 has a half life of about 5,730 years. If an archeologist examines a bone and finds 6.25%…

A: Given :  Half life of C-14 = 5730 years  % of C-14 = 6.25 %

Q: Americium-241 is widely used in smoke detectors. The radiation released by this element ionizes…

A: Given,  Mass of Am-241 = 5.00 g.  Half life of Am-241 = 433 years.  Here, we have to calculate…

Q: 4. After 24.0 days, 2.00 grams of an original 128.0 gram sample remain. a. How many half-lives…

A: 4) Given that Initial mass of the sample (C0) =128.0 g  Mass of the sample remained after 24.0 days…

Q: I0. Radium has a half-life of 1600 years. This means that after four half-lives, the total…

A: Since you have posted multiple questions as per guidelines we can answer one per session . If you…

Q: Which one of each pair of nuclides would you expect to have thelonger half-life?a. Cs-149 or Cs-139…

A: The nuclides which have longer-half life has to be given, One can find the stability of the nuclide…

Q: Radium-226 (atomic mass - 226.03), the only naturally occurring isotope of this element, follows the…

A: Since the half-life of the 2nd and 3rd decay are very small in comparison to the 1st one, the 2nd…

Q: Radioactive Decay of Carbon-14 100% 75% Amount of carbon- 14 50%- 25%- 12.5% 0. 5730 10,740 16,110…

A: Half life is the time taken for Decomposition of 50% of the the total amount of the substance.

Q: 7. Which of the following is the alpha particle? A. 0+1e B. 0-1e C. 10 n D. 42 He 8. A 200 g sample…

A: Given that, Among the given particles, Choose alpha particle = ?

Q: 3. Suppose a sample of carbon-243 has a half-life of 3427 years. How long does it take for 80% of a…

A: In this question, we have to find out the correct answer of given problem by the help of the…

Q: 4. The half-life of radioactive radium-224 is 3.50 days. What was the original mass if 0.200 g…

A:

Q: Calculate how long will it take for a sample of a radionuclide with a half-life of 39.9 days decay…

A:

Writing and Balancing Nuclear Equations

A nuclear equation is a symbolic representation of a nuclear reaction using certain symbols. It is studied in nuclear chemistry and nuclear physics.