If you have 2.00 grams of a radioisotope, with a half-life of 5 days, how much of the isotope is left after 15 days?

Q: The half-life of strontium-90 is 28.0 years. How many grams of this nuclide in a 4.60-g sample will…

A: Half-life time t12=0.696k;   k is decay constantandt=1kln(m0m)m0 is mass of at time t=0m is mass of…

Q: How long does it take for a radioactive substance to decay from 360 cps to 11.25 cps if the…

A: Half-life is the time required for the reaction to be half completed. It is denoted by t1/2 . For a…

Q: 1. A substance has a mass of 5 grams after decaying for 100 minutes. What was the mass of the…

A: Given that: Mass of substance left after decaying = 5 g Total time for decaying of substance = 100…

Q: (11) Lead-211 is a radioactive isotope with a half-life of 36.1 minutes. How long will it take for…

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Q: The half-life of Lithium-8 (Li-8) is 0.84 seconds. If 400 grams of Li-8 were released to the…

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Q: One of the nuclides in spent nuclear fuel is UU-235, an alpha emitter with a half-life of 703…

A: Given , half life of U-235 = 703 million years. We need to find the time at which the amount of…

Q: A pure sample of tritium, 3H, was prepared and sealed in a container for a number of years. Tritium…

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Q: Technicium-104 has a half-life of 18 minutes.If the initial mass is 100.0g,how much remains after 90…

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Q: If uranium-238 has a half-life of 45 billion years, how many years would it take for a 10-gram…

A: Given  Half life of U-238 (t1/2)   = 45 billion years 1 billion years    = 109 years  45 billion…

Q: After 20 years, only 3.125% of the initial amount of radioactive isotope is left. What is the…

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Q: Uranium-235 decays to Lead-207 with a half life of about 704 million. years. if you find a 1000g…

A: Half life of Uranium-235t12 = 704 million years Initial amount of fossilNo= 1000 gms Final amount of…

Q: The half-life of selenium-83 is 22.3 min. If a sample contains 24.0g of selenium-83, how long will…

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Q: 187 Cs has a half-life of 30.2 years. How many years will it take for a 100.0-g sample to decay to…

A: Given datas –  t1/2 = 30.2 years  t = ?  [A0] = 100.0 g  [At] = 1.20 g

Q: The half life of an isotope is 43 seconds.how long does it take 100.00 g of isotope to decay to 6.25…

A: Given data contains, Half-life of an isotope is 43 seconds. Mass of isotope before decay is 100.0 g.…

Q: The half life of Carbon-14 is 5730 years. Calculate what percentage of C-14 will remain after 17,190…

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Q: The radioisotope radon-222 has a Half-Life of 3.8 days. How much of a 73.9-g sample of radon-222…

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Q: After 60 days, 10 grams of radioactive isotope remains from an original 27 g sample. What is the…

A: Given,

Q: Iodine 1 31 has a half life of about 8 days.  In 40 days what percent of the original sample would…

A: Formula used :-  t1/2 = .693/k  Where k is rate constant. k = 2.303/t log [A0]/[A]

Q: After 119 days have elapsed, 1/12 of a radioisotope sample remains undecayed. What is the half-life…

A: Amount of radioisotopes remaining = 112 of the initial amount Number of days taken for the decay =…

Q: Iodine-131 has a half-life of 8 days. What fraction of the original sample would remain at the end…

A: Half life is the period at which concentration of reactant reduces half of its original value.

Q: Radioactive iodine (Iodine-131) has a half-life of 8.04 days. How long will it take for 150g of…

A: Given: The half-life of Iodine-131, t12 = 8.04 days. The initial amount of Iodine-131, (N0) = 150 g.…

Q: You have a sample of Bismuth-212 to prepare for an upcoming medical test.  This isotope has a…

A: The radioactivity follows first-order kinetics. The half-life relates to the rate constant, k for…

Q: The half-life of carbon-14 is about 5715 years. A sample contains 1 gram of carbon-14. How much will…

A: Formula for half life,  N (t )= No(1/2)t/t1/2 where, N (t) = quantity of the substance remaining…

Q: A wooden statue found in Egypt has a carbon-14 content that is three-fifths of that found in living…

A: Given: A wooden statue found in Egypt has a carbon-14 content that is three-fifths of that found in…

Q: The half life of an isotope is 43 seconds. How long does it take 100.0g of that isotope to decay to…

A: Half life = 43 second k = 0.693half life= 0.69343 sec=0.016 s-1

Q: PET scans require fluorine-18, which is produced in a cyclotron and decays with a half-life of 1.83…

A: Given: Half life, T1/2 = 1.83 hrVelocity of transport, v= 60.0 miles/hrfinal Concentration of F-18 =…

Q: Iodine-131 has a half-life of 8.0 days. How long will it take 10 μg of 131I to decrease to 1/100 of…

A: We have given the half life of 131I that is t1/2 = 8 days from this we can find the out the decay…

Q: Radioactive Decay The half-life of radium-226 is 1590 years. (a) If a sample has a mass of 150 mg,…

A: Radioactive decays follow first order kinetics. k=0.693t1/2 Calculate k. k=0.6931590 years…

Q: A sample has a half life of 100 years. If it has been 200 years since it started to decay and there…

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Q: 2. The isotope cesium-137 has a half-life of 29.75 years. How long will it take a 100 gram sample of…

A: First-order reaction: The type of reaction which depends only on one substance is called a…

Q: The half-life of a radioactive isotope is 12.8 seconds. Starting with 0.960 g of this isotope, how…

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Q: 187 Cs has a half-life of 30.2 years. How many years will it take for a 100.0-g sample to decay to…

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Q: Proton-85 has a half-life of 10 years. Approximately what percentage of Kr-85 produced from the…

A: Half life of Kr-85 = 10 yr % of Kr remain active = ?

Q: At a given time, there are 1.2 mg of a radioactive substance present. After 6 hours there is only…

A: To solve this question, first find out the rate constant of radioactive substance and using that…

Q: After 19 days have elapsed, 1/21 of a radioisotope sample remains undecayed. What is the half-life…

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Q: The radioactive substance neptunium -139 decays to 72.85% of its original amount after 28 hours. How…

A: For radioactive decay, relation between rate constant and its concentration is give below.…

Q: If a rock sample was found to contain 1.27 x 10-7 mol of argon-40, how much potassium-40 would also…

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Q: If 20% of the radioactive substance disappears in one year, find its half-life assuming exponential…

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Q: The isotope cesium-137 has a half-life of 29.75 years. How long will it take a 100 gram sample of…

A: Radioactive decay reactions are first order reactions. The calculation can be done using first order…

Q: It is well known that any radiocarbon takes several decades to disintegrate. In an experiment, only…

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Q: If an ancient piece of wood is found to have one-sixteenth the original amount of carbon-14 in it,…

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Q: Plutonium-239 has a half life of 2.41x10* yr. If you have a 10.0 mg sample how much will remain…

A: The time where any substance/element gets remained just half of its actual quantity is considered as…

Q: The half-life of I-131 is 8.0 days. If a medical treatment involves a dose of 100. mg of I-131, how…

A: The remaining I-131 isotope after 16 days is calculated as shown below. where t1/2 is the half-life,…

Q: After 60 days, 10 grams of radioactive isotope remains from an original 38 g sample. What is the…

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Q: Polonium 209 (Po-209) has a half life of 103 years. How long would it take a 100-g sample to decay…

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Q: After 119 days have elapsed, 1/21 of a radioisotope sample remains undecayed. What is the half-life…

A: Suppose the initial amount of sample be Ao After 119 days, amount remaining, A = (1/21) Ao The…

Q: Iron-59 has a physical half-life of 45 days. If 96 g of a radioactive iron sample (59Fe) is received…

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

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Q: The isotope Np-238 has a half life of 2.0 days. If 96 grams of it were present on Monday, how much…

A: Here given, The half-life of Np-238 (t1/2)= 2 days. Initial amount present (N0) = 96 g Time (t) = 6…

Q: A 371.9 ng sample of an unknown radioactive substance was placed in storage and its mass measured…

A: On passing a half life the concentration of the substance becomes half. Let the substance has passed…