A quantity of a radioactive element gives 1,200 alpha particles every 60 seconds, and after 120 minutes have passed, its activity has become 150 decays per minute, so the half-life is .

Q: The radioactive isotope (1Os) has a half-life of 22.1 hours. How much of 49.5 g of this isotope will…

A: If initial quantity is N0 and after t time the quantity is N then…

Q: A 416 g sample of sodium-24 decays to 13.0 g of sodium-24 within 60.0 hours. What is the half-life…

A: Given data: The initial quantity is N0=416 g. Quantity after decay is N(t)=13.0 g. Time elapsed is…

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

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Q: If you are told the half life of a material is 3,500 years, then how much would be remaining from a…

A: Given data: Half life (t1/2)= 3,500 years Initial quantity of the substance (N0) = 10 g Time elapsed…

Q: The half-life of Carbon-14 is 7 years. How much of an initial 168 g sample will remain after 30…

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Q: The half life of Thorium is 75,000 years. How much of the substance will be left after 3 half lives

A: Let initial amount of substance is m. The half life is T= 75000 years.

Q: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…

A: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…

Q: When a nucleus of emits an alpha particle, what are the atomic number and the atomic mass of the…

A: In alpha decay, an unstable nucleus will emit an alpha particle, which is a helium nucleus composed…

Q: If there were originally 400 grams of carbon-14 in an object, how many grams would remain after…

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Q: When we measure the rate of radioactivity of a given isotope 60 days after making an initial…

A: The time of management is 60days

Q: A radioactive material decays at a rate proportional to its amount . If the material has a half-life…

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Q: A sample of carbon-14 has been decaying for 22 920 years and is now 35,0 grams. (The half-life of…

A: Decay constant and half life are related as,  k=0.693t12

Q: The half-life of radium-226 is 1600 years. How long will it take for 10.0 mg of radium-226 to decay…

A: Using half life concept to solve the problem

Q: Cobalt-60 has a half-life of approximately 5 years. If 53g of the material was stored for 20 yers,…

A: mi=m0×2nmi: initial mass=53 kgm0=remaining mass n= number of periods

Q: A sample containing 1 gram of Radium-224 was stored in laboratory 100 years ago. Now the sample…

A: Given data: The mass of Radium-224 at 100 years ago is m0=1 g. The mass of Radium-224 at now is…

Q: A Geiger counter registers a count rate of 4,800 counts per minute from a sample of a radioisotope.…

A: Given data:  Initial count rate (N0) = 4,800 counts per minute Time (t) = 10 minutes Remaining count…

Q: A 85.0-kg person is exposed to 389 rad of radiation. How many joules did this person absorb?

A: Given, Exposed radiation= 389 rad 1J/kg = 100 rad Mass (M)=85 kg Total energy absorbed (T.E)=? We…

Q: Certain radioactive substances has a half-life of 20 min. If there is 56 lbs of it right now, how…

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Q: A radioactive material has a half-life of eight days. How long will it take for the material to be…

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Q: The half-life of a particular element is 330 days. What is its decay constant?

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Q: A radioactive isotope has a​ half-life of about 17 ​years, which means that if it starts with 1 kg…

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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: Given data The half-life of the cesium-137 is t1/2 = 29.75 years. The initial amount of the…

Q: How long will it take for an amount of Radon-223 to decay to only 60% of the original amount? The…

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Q: A sample of polonium-208 has a half-life of 2.898 years. What percent of polonium-208 remains after…

A: The half-life of a radioactive substance is the time required for a quantity to reduce to half of…

Q: A radioactive source has a half-life of 80 s. How long will it take for 7/8 of the source to decay?

A: Given, the half life a radioactive source =80 s we have to calculate the time for 7/8 of the source…

Q: The radioactive element 2760Co  has a half life of ______ years. If you had a sample of 17 g, about…

A: Given: The mass of sample (m) = 17 g. The half-life of cobalt (T1/2) = 5.27 years. The life of…

Q: The activity of a radioactive element falls from 600 s1 to 500 s1 in 40 minutes. The half-life of…

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Q: How many neutrons are in uranium-235?

A: The number of protons equals the atomic number. The number of protons and neutrons together…

Q: cadmium -107 has a half -life of 6,52 hours .if you start off with sample which sample which has an…

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Q: The half-life of l-137 is 8.07 days. If 25 grams are left after 40.35 days, how many grams were in…

A: The formula of the radioactivity is  where, N is the amount left, No is the initial amount, t is…

Q: A radioactive substance plutonium-239 has a half-life of 24,000 years. Initially, there is 700 mg of…

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Q: What is the half-life of a radioactive isotope if the activity of a sample drops from 14,080 cpm to…

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Q: What happens when one kilogram of uranium undergoes nuclear fission?

A: to find : what happens when 1 kg of Uranium undergoes nuclear fission

Q: A certain radioactive substance has 122,200 atoms with a half-life of 12 minutes. NOTE: This is a…

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Q: A clinical technician finds that the activity of a sodium-24 sample is 1,024 cpm. What will be the…

A: Half life is defined as the time required for the radioactivity of a radioactive element to drop to…

Q: f the half-life of cesium-137 is 30 years, approximately how much time will be required to reduce a…

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Q: If the half-life of an isotope is two years, what fraction of the isotope remains after six years

A: Amount of radioactive material after time t is given by: N = N0*exp(-lambda*t) lambda = decay…

Q: A radioactive species has 128 atoms present. If it has half-life of 5 years, calculate the number of…

A: Write the given values of this problem. N0=128 atomst=20 yearst12=5 years

Q: The half life of 85Kr is 11 years. What is the mass of one millicurie of 85Kr? O 9.2 microgram O 30…

A: Given  Half life = 11year  T½= 11*365*24*60*60 sec =3.48*10⁸ sec I millicurie = 3.7*10⁷ /s  Lambda=…

Q: A sample of a radioactive element has a half-life of 180 days; what percent of this sample will…

A: The decay constant of a radioactive sample is given by :  The amount of sample left after 't' time…

Q: radioactive sample

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Q: A radioactive nuclide has a half-life of 10 seconds. Beginning with 256 grams of the material, how…

A: Given: Half life period t1/2 = 10 sec Initial concentration N0 = 256 g Time = 1 min = 60 sec = 6…

Q: How many radioactive nuclides are in a sample with a radioactivity of 3.1 kCi? The half-life of the…

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Q: The radioactive isotope thorium 234 has a half-life of approximately 578 hours. (a) If a sample has…

A: Expression for decay constant -  λ=0.693Half life Given value-  Half life = 578 hours  Therefore,…

Q: A team of biologists finds a mammoth frozen in permafrost. They analyze the fraction of Carbon-14…

A: this question is about exponential growth and decay. we find the actual how old animal is by carbon…

Q: If we start with 6.4*10^12 atoms of a radioactive material with a half life of 1.2 days, how many…

A: Half life of radioactive material is the amount of time takes for half of a particular sample to…

Q: A radioactive element has a half-life of 33 years. What is its continuous rate of decay?

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Q: The initial amount of carbon-14 is 100 g and the amount of carbon-14 dropped to 1 g after decay…

A: Given, Initial mass (mo) =100g Final mass (m) = 1g half life (t1/2) =5730 years