what fraction of a radioisotope has decayed after two half-lives?

Q: The half-life of nucleus Rn-222 is 3.88 days. How many mg of a 5000 mg sample of Rn-222 remains…

A: The half life of a given reaction refers to the time required by a given compound to reduce to half…

Q: Iodine -125 emits gamma rays when it decays to Tellerium -125 and has a half life of 60 days. If…

A: Given, half life of Iodine -125 t1/2 = 60 days            initial mass of Iodine -125 = 0.020 g The…

Q: Calculate the half-life of a radioisotope if it decays to 12.5% of its radioactivity in 12 years.

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Q: Nitrogen-13 is used in tracers injected into the bloodstream for positron emission tomography (PET).…

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Q: The half-life of a decaying radioactive isotope is the time it takes for half of the original mass…

A: Here we are required to find the half life of the radio isotope

Q: Determine the half life of an isotope hat decays from 450.0g to 320.0g in 50 years.

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Q: Fluorine-18, which has a physical half-life of 110 min, is used in PET scans. if 1.00g of…

A: The fluorine-18 sample was shipped at 5:00 PM and arrives the laboratory at 9:30 AM in the next…

Q: Radium 223 decays with a half life of 11.4 days. How long will it take for a 0.240mol sample of…

A: Half life of radioactive elements is given by    t1/2 =0.693λ      λ = disintegration constant.…

Q: What is the half life of radioistope if it decays to 12.5% of its radioactivity in 12 years?

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Q: The half-life of 18F, which is utilised in medical imaging, is 110 minutes. After 300 minutes, what…

A: Given half life = 110 minutes time = 300 minutes

Q: If 28.0% of a sample of sodium-24 decays in 7.11 hours, what is the half-life of this isotope (in…

A: Given data,  Let, Initial amount of sample is [A]o=100% 28 % of sample is decay so remaining amount…

Q: The half-life of molybdenum-99 is 67 h. A 200 microgram (mg)quantity decays, over time, to 25 mg.…

A: Solution :      The half-life of a reaction is defined as the time required to reduce the…

Q: Iodine – 125 emits gamma rays when it decays to Tellerium-125 and has a half-life of 60 days. If a…

A: The radioactive decay always follows the first order kinetics. The radioactive decay of I-125 must…

Q: Nitrogen-13 is used in tracers injected into the bloodstream for positron emission tomography (PET).…

A: The half-life (t1/2) of Nitrogen-13 is provided as 10 minutes.

Q: Calculate the half-life of a radioisotope if it takes 24 years for a sample to decay to 12.5% of its…

A: Radioactive decay follows first order kinetics. Half-life is the time taken by a radioisotope to…

Q: In 1954 researchers found an ancient Egyptian ship that was buried near the Pyramids approximately…

A: Given The half-life period for 14C = 5730 y = 1.8 x 1011 sec. Molar mass of 14C = 14 g/mol NA =…

Q: Cobalt-60 is a strong gamma emitter that has a half-life of 5.26 yr. The cobalt-60 in a radiotherapy…

A: All radioactive decays are first order reactions. The integrated rate law for 1st order reaction is…

Q: 1. Co decays with a half-life of 5.27 years to produce 2Ni. (a) Calculate the fraction of a sample…

A: Given a radioactive decay of cobalt to nickle. All radioactive decay follow first order kinetics…

Q: The decay constant for the element X is 6.931 yr⁻¹. What is the half-life?

A: Relation between decay constant (K) and half life (t12) of an element:-t12 =0.693K

Q: How many years will it take for 50 microcuries of tritium (Hydrogen-3) to decay to 3.125…

A: The given reaction will follow the first order kinetics

Q: The half-life of 123I is 13 hr.  How much of a  64 mg sample of 123I is left after 26 hours?

A: The isotope of iodine, 123I, undergoes decay in accordance with first order kinetics. The half-life…

Q: The half-life of 87Sr is 2.80 h. Calculate how much time it would take for an isolated quantity of…

A: Time required to decay for a radioactive molecule,t = 2.303Klogaa-x Where a is the initial amount…

Q: The isotope 166-Yb decays by electron capture with a half-life of 57 hrs. What percentage of the…

A: We have to calculate the percentage of isotope left

Q: he half-life of radioactive Bk-248 is 23.7 h.   How long does it tak

A: Radioactive decay follows the first order kinetics  its decay constant   λ = 2.303t log NoNwhere…

Q: The amount of a radioisotope that remains after two half-lives have passed is:

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Q: The half life of 231Pa is 3.25 x 104 years. How much of an initial 10.40 microgram sample remains…

A: Formula used to calculate the sample that remains after 3.25X105 years,

Q: Determine the decay constants ( in seconds) for iodine and magnesium given half lives are 8.04 days…

A: Relationship between half life and decay constant is given as,

Q: A radioisotope “X” has a half-life of 2.5 years. Determine (to the nearest 0.1 mg) how much of a…

A: All the radioactive reactions follow first order kinetics . The term half life is defined as the…

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

A: Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A…

Q: The half-life of iron-59 is 44.5 days. How much of a 3.00-mg sample will remain after 222.5 days?

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Q: lodine - 125 emits gamma rays when it decays to Tellerium-125 and has a half-life of 60 days. If a…

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Q: The half-life of nucleus Rn-222 is 3.88 days. How many mg of a 5000 mg sample of Rn-222 remains…

A: Given, half-life of nucleus is 3.88 days.  The half-life can be calculated by the expression given…

Q: (5) The half life of sodium-24, which diminishes by first order radioactive decay, is 15.0 hours. A…

A: Given, the half-life is for sodium-24 Time for first order decay = 15.0 hours Now, calculate the…

Q: What is the half-life of an isotope that decays to 6.25% of its original activity in 68.3h?

A: Radioactive decay is a first order reaction. For a first order reaction, rate constant can be…

Q: What is the half-life of an isotope that decays to 3.125% of its original activity in 63.6 h?…

A: We know that,  N(t) = N0(1/2)t/t1/2 No = initial amount  N(t) = amount of substance at time t t1/2 =…

Q: 10.6. A sample of S, a ß- emitter, has an activity of 0.100 µCi. In 20.0 days, the activity o the…

A: Given,  Initial amount, [A]0 = 0.1 µCi  Final amount, [A] = 0.0853 µCi  Time, t = 20 days

Q: If a tree dies and the trunk remains undisturbed for 1.535 × 10⁴ years, what percentage of the…

A: Degradation of the  14C  is as per the first order reaction. We are having half life that can give…

Q: Radium 223 decays with a half life of 11.4 days. How long will it take for a 0.240mol sample of…

A: Half-life of Ra-223 = 11.4days Mass of Ra-223 = number of moles of Ra-223 × Molar mass of Ra-223…

Q: If a tree dies and the trunk remains undisturbed for 1.015 x 104 years, what percentage of the…

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Q: The half-life of stroncium-90 is 28 years. How long will it take a 50-mg sample to decay to a mass…

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Q: 137Cs has a half-life of 30.2 years. How many years will it take for a 100.0-g sample to decay to…

A: Since you have posted multiple independent questions in the same request, we will solve the first…

Q: 8.0mg of a radioisotope of half-life 30 minutes is used for 12 minutes. What is the amount of the…

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Q: Iodine-131 is a radioactive isotope. After 2.00 days, 84.2% of a sample of 13I remains. What is the…

A: Iodine- 131 is an radioactive isotope. Time = 2 days Final concentration of 131l  = 84.2% of sample…

Q: What is the half life of a 100 g sample of nitrogen- 16 that decays 12.5 in nitrogen-16 in 21.6 s?

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Q: A sample of sodium-24 with an activity of 12 millicuries (mCi) is used to study the rate of blood…

A: Radioactive reactions are first order reaction. Initial activity of Sodium-24, No = 12 mCi Half life…