The decay of a radioactive material has a count rate is 2000 decays/min. Four hours later, the decay rate is 500 counts/min. What is the half-life?

Q: A radioactive material produces 3.522E+3 decays per minute at one time, and 5.47 h later produces…

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Q: The activity of a freshly prepared radioactive sample with a half-life of 4 days is 1000 Bq. How…

A: Given : t1/2 = 4 days No = 1000 Bq N = 250 Bq

Q: 1. The decay of radioactive substance is given by 7 N = Noe (1), where N is the number of atoms…

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Q: radioactive

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Q: Atts, you have a pure sample of an unknown substance. At t= 293 s, 36.8% of the substance remains.…

A: Radioactive substance remaining at t=293s, N=36.8100×N0=0.368N0

Q: How many half-lives would have to elapse for a sample of a radioactive isotope to decrease from an…

A: No = 192 cpmN = 3 cpm

Q: A radioactive sample with a half-life of 3.1 s initially has 10,000,000 nuclei. What would be the…

A: The activity is  R=11955.3677Bq

Q: An 1 g sample of a radioactive element takes 83.92 million years to reduce into 1 µg. Calculate the…

A: Radioactive decay takes place when an unstable nucleus becomes stable. The instability arises due to…

Q: If a 3.16-g sample of an isotope having a mass number of 135 decays at a rate of 0.530 Ci, what is…

A: Given Mass of Isotope = 3.16 gram = 3.16×10-3 Kg Mass Number = 135  Rate of decay = 0.530 Ci As…

Q: A freshly prepared sample of a certain radioactive isotope has an activity of 3,7 × 1011 decays/s.…

A: Given quantities: initial activity of the isotope (A0) = 3.7 × 1011 decays/s activity of the isotope…

Q: The main dangerous radioactive material left over after the Chernobyl disaster is Caesium-137. The…

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Q: the decay constant or the beta decay of ^99 43Tc was found to be equal to 1.0x10-13/s. What is the…

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Q: a sample with a half-life of 19 days has an initial activity of 7.0 x 10^5 counts/s. what isits…

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Q: The decay constant of a radioactive source is 752 per year. Then its half- life equals: *

A: Step:1   The  Time  taken  for a radioactive atom    to  disintegrate  to half  of its  original…

Q: What is the mass of 1ci of 227Th? If the half-life is 1.90 years.

A: T1/2 = 1.90 years        = 1.90 x 3.15 x 107 s λ = 0.693/T1/2    = 0.693/(1.90 x 3.15 x107s)

Q: A radioactive sample has a decay constant of 2.97 x 10 s¹¹. Estimate the half-life.

A: Unstable nuclei decay into a stable state. This process is called radioactivity. The rate at which…

Q: What is the half-life of an isotope that decays to 6.25% of its original activity in 60.2 h?

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Q: A freshly prepared sample of a certain radioactive isotope has an activity of 3.7 × 1011 decays/s.…

A: Relation between activity of the radioactive isotope and half life…

Q: A radioisotope was injected in the human body. The half-life of the radioisotope is T/2 = %3D 6…

A: Given: T1/2=6 hours

Q: A tree falls in a forest. How many years must pass before the C activity in 1.00 g of the tree's…

A: mass = 1 g number of atoms = number of moles * avogadro number  = (1/14)(6.022 * 1023) = 4.3 * 1022…

Q: The Half-life of certain radioactive sample is 30 minutes. At 2.00 PM, the decay rate is measured to…

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Q: A sample of radioisotope has a decay constant of 9.976✕10-7 s-1 and prepared with an initial…

A: Given data: The decay constant of a sample of a radioisotope is, The initial activity of a sample…

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Q: A nuclide whose "generic" symbol is 6430X would have protons and neutrons.

A: The generic symbol of a nuclide is given as X3064.

Q: What is the Decay Rate (k), if the Half Life is 10.5 days?

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Q: The counting rate from a radioactive source is 4000 counts per second at time t=0. After 10 seconds,…

A: We know that activity is  N=N0e-λt and  T1/2=ln2λ=0.693λ Using the above formula the problem can be…

Q: Potassium-argon dating is used to measure the age of rocks formed from cooled lava by determining…

A: The radioactive dating of rocks formed from cooled lava is determined by using parallel decay of…

Q: A radioactive material produces 4.386E+3 decays per minute at one time, and 7.57 h later produces…

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Q: A radioactive sample has a decay constant of 0.219 3/minute. (a) What is its half-life? (b) If at…

A: The relation between the half life and the decay constant is  T = 0.693λ The equation of…

Q: The half-life of 60?? is 5.27 years. The activity of a 60?? is 3.50 × 109 Bq. What is the mass of…

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Q: The half-life of a radioactive isotope is 140 d. How many days would it take for the decay rate of a…

A: Given that, Half life of the isotope, T = 140 days  We know that,  The half life is the time in…

Q: Plutonium-239 (atomic number 94) is a by-product of nuclear power plants. It decays via alpha and…

A: A) decay constant = 0.693/half life = 0.693/24100 = 0.0000287 yr-1 = 0.693/(24100*365*86400) = 9.12…