3. Natural thorium consists entirely of the alpha-radioactive isotopes 232Th which has a half-life of 1.4 × 1010 y. If a rock sample known to have solidified 3.5 billion years ago contains 0.1 percent of 232Th today, what was the percentage of this nuclide it contained when the rock solidified?

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: An isotope of lead, 201Pb, has a half-life of 8.4 hours. How many hours ago was there 40% more of…

A: Chemical kinetics is branch of chemistry in which we deal with speed at which rate of reaction…

Q: If you have 1 gm of pure potassium 40 (40K) that is experimentally determined to emit about 105 beta…

A: Activity of 40 K = 105 beta rays. The decay constant λ can be calculated as follows:

Q: Isotope of uranium 234U decays to thorium by the alpha decay with the half-life of 7.73 x 1012 s.…

A:

Q: on 5 A The nuclide As-76 has a half-life of 26.0 hours. If a sample of As-76 weighs 344 g, what mass…

A:

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

A:

Q: The rate constant for a certain radioactive nuclide is 9.4 x 103h-1. What is the half-life of this…

A:

Q: The rate constant for a certain radioactive nuclide is 9.8 x 10-3h-1 . What is the half-life of this…

A: The rate constant for radioactive nuclide is given as 9.8 x 10-3h-1. All the radioactive decays…

Q: Strontium-90 is radioactive and has a half life of 28.8 years. What percentage of a sample would be…

A:

Q: Gallium-67 is used medically in tumor-seeking agents. The half-life of gallium-67 is 78.2 hours. If…

A:

Q: In a moon rock sample, the ratio of the number of stable 4°Ar atoms present to the number of…

A:

Q: The half-life of radium-226 is 1.60 × 10' yr. How many hours will it take for a 2.50-g sample to…

A: The decay reactions are first order reactions. Hence for the first order reactions we can say that…

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: A radioactive isotope decays from 60 grams to 15 grams in 20 seconds. What is its half-life?

A: Given is the radioactive isotope.We know any radioactive decay follows first order  reaction…

Q: The half-life of Radium-226 is 1600 years. If 30 grams are left after 8,030 years, how many grams…

A: Radioactive decay follows first order kinetics.  k = 0.693/t0.5  Or, k = 0.693/1600 year^-1 =…

Q: Gallium-67 is used medically in tumor-seeking agents. The half-life of gallium-67 is 78.2 hours. If…

A: Given-> Half life = 78.2 hours Initial amount = 44.2 mg Time = 97.0 hours

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: Gallium-67 is used medically in tumor-seeking agents. The half-life of gallium-67 is 78.2 hours. If…

A:

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

A: The half-life is the time required to reduce one half of the initial concentration of the substance.

Q: The half-life of tritium is 12.3 years. If 48.0 mg of tritium is released from a nuclear power plant…

A: Given data contains, Half-life of tritium is 12.3 years Mass of tritium is 48.0 g Time t is 5.0…

Q: How long would it take for the amount of u-235 to reach 1/8 of its initial amount? One of the…

A:

Q: Americium-241 is a radioactive isotope that is used in smoke detectors. It has a half-life of 432.2…

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Q: A sample of a newly discovered element, West Virginium, has a half-life of 288 years.  How long…

A:

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: Potassium-40 decays to argon-40 with a half-life of 1.27 * 109 yr. What is the age of a rock in…

A: It is given that potassium-40 decays to Argon-40 and has a half-life of 1.27×109 years and the mass…

Q: A radioisotope has a half-life of 8.7 h. What mass of the radioisotope will be left after 24.5 h if…

A: The objective of the question is to find out the the mass of radioisotope left after 24.5 h.

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…

A:

Q: Thallium-201 is used medically to diagnose heart problems. The half-life of thallium-201 is 72.9…

A: Decay reactions are first order reactions. Since we know that, for different order of reactions, the…

Q: Strontium-90, a beta emitter, has a half-life of 28.1 yr. If 29.1 mg of 90Sr were incorporated into…

A:

Q: The half-life of C-14 is 5730 years. How many grams of carbon-14 will remain after 17190 years, if…

A:

Q: Chemistry An unknown radioactive substance has a half-life of 3.20 hourshours . If 34.7 gg of the…

A: All natural and artificial radioactive decays follows first order kinetics The integrated rate…

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

A: The relationship between the decay constant and the half-life period is given below.

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

A: Given data,Half life(t1/2)=1.83hoursSpeed=60.0miles/hrLet initial concentration of F-18 be 100Final…

Q: The Cs-131 nuclide has a half-life of 30 years. After 120 years, 3.3 g remain. What is the original…

A: Answer

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: A radioactive isotope emits 999 disintegrations per minute due to beta decay. If after 1.01 years…

A: Since the relationship between activity and time is given by  A0 e-λt = A where A = activity after t…

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…

A:

Q: Gallium-67 is used medically in tumor-seeking agents. The half-life of gallium-67 is 78.2 hours. If…

A:

Q: 3. Suppose a sample of carbon-243 has a half-life of 3427 years. How long does it take for 80% of a…

A: In this question, we have to find out the correct answer of given problem by the help of the…

Q: Carbon-14 has a half-life of 5715 years. It is used to determine the age of ancient objects. If a…

A:

Q: A certain radioisotope has a half-life of 9.54 days. What percentage of an initial sample of this…

A:

Q: Radioactive decay can be described by the following equation In A = In Ao - kt where Ao is the…

A:

Q: Ca-60 is used extensively in radiotherapy, its half-life is 5.27 years. How many years will it take…

A: The given data is as follows: The half life Co-60 = 5.27 years The initial amount A∘= 100 The left…

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…

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.