How long does it take for 87.5% of each isotope to decay? Kr-91 Kr-89 min Kr-79 h Kr-81 yr

Q: A dinosaur remain has a C-14 isotope and has a half-life of 5,715 years. The activity of this is…

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Q: a. Two or more nuclei combine to form one larger nucleus in the process of nuclear_ i) fission, ii)…

A: We need to fill answers for the given short questions.

Q: How much time in years (assume a 365 day year for each year) would it take for a 1.805 g sample of…

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Q: How much time is required for a 6.25-mg sample of 51Cr to decay to 0.75 mg if it has a half-life of…

A: The initial amount of the sample = 6.25 mg The amount of sample after time t = 0.75 mg. The…

Q: How much time in minutes would it take for a 2.301 g sample of 3H to decay to a mass of 1.789 g if…

A: The initial concentration (N0), final concentration (N), and time (t) required to convert the…

Q: How many days will it take for a radioactive isotope with a half-life t1/2 = 134 days to decay to…

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Q: 222Rn has a half-life of 3.82 days. If a sample contains 36.2 mg of 222Rn, what mass of the isotope…

A: We have to calculate the amount after 6.81 days.

Q: How long will it take for 2.35mg of Pu-236 with half life of 2.86 years to decay to 0.100 mg? О а.…

A: Given: Remaining mass = 0.100 mg Initial mass = 2.35 mg Firstly, the ratio of the remaining mass to…

Q: -33. The number of radioactive nuclides in a sample decays from 1.00 × 1020 to 2.50 × 10º in 10.0…

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Q: How many half lives will it take for 50 g of "Tc to decay to 6.25 g?

A: Half-life period was discovered by ernest Rutherford in 1907. Rutherford applied the principle of a…

Q: The half-life of uranium-238 is 4.5 billion years. What is the decay constant for uranium-238? A)…

A: The nuclear reactions are of first order reaction and its half-life is nothing but the amount of…

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: Half-life of Cs is 30.2 years. Intial amount sample = 100 g  Final amount sample = 1.00 g

Q: Which type of decay happens when neon-19 decays into fluorine-19? The atomic number of neon is 10;…

A: Given nuclei is 19 -Ne For Ne ;     Atomic number = 10     Mass number = 19 After decay it converts…

Q: 27, What decay mechanism is involved in the transformation of 1Au to r? 179 decay decay b. +B decay…

A: Nuclear reaction: The given reaction is a nuclear reaction. In the nuclear reaction, one nuclide is…

Q: Calculate the time required for 52% of a sample of A (t1/2 = 7510 y) to decay.

A: Given that : The half-life of sample A (t1/2)= 7510 y We have to calculate the time required for 52%…

Q: What is the half‑life of an isotope that decays to 6.25%6.25% of its original activity in 57.1 h?

A: The half-life of the isotopes can be described as the time at which the amount of the activity…

Q: 137 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 half life = 30.2 years initial Concentration = 100 g Concentration at time t = 0.900 g

Q: 1a) How long will it take for 30 g of 222Rn to decay to 7.5 g? 1b) How many grams of 1°N will be…

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Q: How many half-lives have passed in each of the following situations? (a) Initially the sample is…

A: SOLUTION: Step 1: (a). Half-life is the interval of time required for one-half of the atomic nuclei…

Q: Radium-221 has a half life of 30 seconds. How long will it take for 82% of a sample to decay?

A: Half life =30 seconds Decay percentage = 80%

Q: An unknown radioactive element decays into non-radioactive substances.  In 660 days the…

A: Rate constant (k)= 2.303/t log 100/49 So k = (2.303/660) ×0.3098 =0.0011 days ^-1

Q: 1.What is the half-life of 99Tc if a 500.0 g sample decays to 62.5 g in 639,000 years 2)How much of…

A: Given,Mass 500 g,Therefore, the first half-life is 250.0g.Second half-life is 125.0g.Third half-life…

Q: Half life iridium 192 is 106.51 days. How many days are required for 60 mg to decay to 7.5 mg

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Q: Radium 223 decays with a 1/2 life of 11.4 days. How one will it take for 0.240 mol sample of radium…

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Q: isotope with a half-life of about 22 minutes. How much time will it take for a sample of Fr-223 to…

A: Radioactivity follows first order kinetics,  Half life time (t1/2) = 22 minutes  k = 0.693/t1/2 =…

Q: The half-life of a radioactive element is 8 days. How long will it a 1.0 g sample to decay to 0.0625…

A: Radioactive decay is the process of breakdown of radioactive matter. The atomic nucleus is broken…

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

A: Given,Half life of 123I is 13 hr

Q: 2 mol of beryllium-8 nuclei combine to form 1 mol of oxygen-16. The mass decrease is 0.0157 g.…

A: Solution Nuclear reactions, like chemical reactions, ar in the middle of changes in energy. The…

Q: 137 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: Cobalt-60, which undergoes beta decay, has a half-life of5.26 yr. (a) How many beta particles are…

A: Half life: It is the amount of time taken by a radioactive material to decay to half of its original…

Q: How much of a 0.230 g radioactive sample with a half-life of 8 hours would remain after a period of…

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Q: An unknown radioactive element decays into non-radioactive substances. In 340 days the radioactivity…

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Q: 239Pu is a nuclear waste byproduct with a half-life of 24,000 y. What fraction of the 239Pu present…

A: Given data, t1/2 of P239u = 24,000 yTime (t) = 1000 years To calculate the fraction of the 239Pu…

Q: For a radioactive isotope with t1/2 38.7 hr, how many hours will it take for a 3.27 mCi sample to…

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Q: The radioactive cobalt isotope, "Co, has an half-life of 63 months and undergoes decay. The m of Co…

A: From the data  A) We are calculating number of moles of cobalt after 5 years B) The activity of…

Q: ²⁷Al is the only stable isotope of aluminum. Predict how ²⁴Al and ³⁰Al will decay. A) β⁻ decay…

A: A)

Q: What is the half-live of a radioactive isotope if it takes 6.2 days for a 72g sample to decay to…

A: Given, 72 g to decay to 18 g. t = 6.2 days To calculate the half-life.

Q: 21. Half-Life The half-life of radium-226 is approximately 1620 years. a. How much of a sample…

A: Introduction: We know that this decay of radioactive elements is a type of first-order reaction. The…

Q: 3. 137Cs 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: 14Cdecays by B-emission and after 12.0 h, ninety percent of the radioactive substance remains.…

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Q: Duestion 4 How much energy is released by the decay of I gram of 2307h in the following reaction.…

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Q: A rock contains a Pb-206 to U-238 mass ratio of 0.473:1.00. Assuming the rock did not contain any…

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Q: A radionuclide undergoes beta decay with half-life of 30.0 years. How many years will it take for 25…

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Q: The half life of radium-226 is 1600 years. How many grams of a 0.25g sample will remain after 4800…

A: After decying the nucleus it emits radiation of electromagnetic rays ,of certain Wavelength.

Q: A theoretical isotope known as Du-30 has a half life of 6 months. The amount decreased from 1.50M to…

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Q: Even though plutonium−239 (t1/2 = 2.41 × 104 yr) is one of the main fission fuels, it is still a…

A: All radioactive processes are first order reactions.

Q: A patient is given 0.050 mg of Tc-99. How long until the isotope decays to 6.3 x 103 mg? (Half life…

A: Given  Mass of Tc-99  [ A0 ] = 0.050 mg  Remaining Tc -99 [ At ] = 6.3 × 10-3 mg  Half life ( t1/2 )…

Q: If 600,0g of 14C decays after 3 half lifes, how much of the sample would remain ( in grams)?

A: Recall the following relation to calculate amount of radioactive sample remain after a definite time…

Q: The half-life of a particular radioactive isotope X is 10.0 days. (1) Determine its decay constant.…

A: half life = 10.0 days.

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.