What is the half-life of a radioactive isotope if the activity of a sample drops from 6,080 cpm to 190 cpm in 21.0 min? Answer needs to have significant figures. I got 4.2 min as my answer but am told it is wrong.

Q: A sample of the isotope 131I, which has a half-life of 8.04 days, has an activity of 5.0 mCi at the…

A: Given: The half-life of the sample =8.04 days The activity of the sample = 5.0 mCi The activity of…

Q: The nuclide 14C contains (a) how many protons and (b) how many neutrons?

A:

Q: Suppose that you start with 3.65 g of a pure radioactive substance and determine 19.6 h later that…

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Q: After how many half-lives will (a) 10.0%, (b) 5.00%, and (c) 1.00% of a radioactive sample remain?

A: Formula to calculate the number of half-lives is,

Q: The probability that a randomly chosen nucleus in a radioactive sample will have decayed in a given…

A: Sample of radio active nucleus decayed = 96.875 %

Q: The following data are obtained from sources A and B of the same isotope: Timing Period Source A +…

A: In this question we have to find the ratio of activity and the percent standard deviation. Please…

Q: A radioactive substance decays according to the following function, where y, is the initial amount…

A: y(t) = yoe-0.072t Where yo is the initial amount present of a radioactive compound y (t) is the…

Q: A sample of the radioactive nuclide 199Pt is prepared that has an initial activity of 7.80×1011 Bq…

A: a) We know ,   half life t12=t ln2ln NoNtinitial activity = 7.8x1011next activity = 9.45x1010

Q: The half-life of americium-241 is 457 years. What is the activity in curies of a 0.010g of sample of…

A: Half life of americium 241  t1/2 = 457 years Mass of sample m = 0.010 g Molar mass of americium -241…

Q: A radioactive sample has a mass of 999 grams. How much remains after 2 half-lives?

A: If the amount of a radioactive sample is N0 initially, then after 1st half live of the sample, it…

Q: Q10: Using a nuclear counter the count rate of emitted particles from a radioactive source is…

A: Given value--- at t = 0 , count rate = 1600 count/s. after 6 second , count rate = 100 count/s. We…

Q: Manganese-52 has a half-life of 6 days. How many days would a scientist have to wait for the…

A: The radioactivity decay of a sample has a relationship given by:Nt=N0e-λt………(1)where,N0 is the total…

Q: Two nuclei have mass number in the ratio 1 : 3. What is the ratio of their nuclear densities?

A: Given that, Two nuclei have the mass number in the ratio 1 : 3. The nuclear densities of nuclei A is…

Q: QI: A hospital technician is working with a radioactive source. The graph below shows the activity…

A: The given graph is shown below

Q: The half-life of iodine-131 (131I)(131I), an isotope used in the treatment of thyroid disorders, is…

A: Write the relation between decay constant to the half life.

Q: Which expression correctly describes the radioactive decay of a substance whose half-life is T?

A: Radioactive decay is given by , Nt = N0e-λt And rate constant λ = ln2t1/2 = ln2T

Q: What is the nuclear equation for Gd (alpha decay)? 64

A: Answer C

Q: What is the binding energy per nucleon of 24 Pb? Give your answer in MeV

A: Mass defect of Pb is

Q: The half-life of radium 224 is about 3.6 days. What approximate fraction of a sample remains…

A: Half Life of Radium 224, t1/2 = 3.6 days Time interval, t = 2 weeks = 14 days

Q: When radium 226 decays emitting an alpha particle, what is the atomic number and atomic mass of the…

A: The alpha particle having mass number 4 and atomic number 2 and it is a helium nucleus.

Q: The half-life of radium is approximately 1600 years. If the present amount of radium in a certain…

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Q: Both 1) Equation for a radioactive decay of a nucleus is  dNdTdNdT=−??. Given decay constant is λ =…

A: The question is regarding radioactive decay of the nucleus and half life.

Q: The initial activity of a sample of the cesium isotope 137 Cs is 150 mCi. When delivered to a…

A: Given: The initial activity (A0) of the sample is 150 mCi. The activity (A) after a time (t) of 12…

Q: What fraction of radioactive nucleus sample survive after two half-lives?

A: Half-life is the time taken by the radioactive element to become the half of the original amount as…

Q: Determine the half-life (in s) of a radioactive sample that has a decay rate of 3.30 ✕ 1011 Bq when…

A: Given. N = 1.7*10¹⁵  dN/dt = 3.3*10¹¹ Formula used  N(t) = N⁰*0.5t/T Where  T is half life

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: Radium decomposes at a rate proportional to the amount present. In 100 years, 100 mg of radium…

A: Given: The time is t=100 yr. The initial amount of radium is No=100 mg. The final amount of radium…

Q: A Geiger counter reading of a radioactive sample is initially 7020 counts per minute. The same…

A:

Q: After 2.00 days, the activity of a sample of an unknown type radioactive material has decreased to…

A: Formula to calculate the activity

Q: what type of radioactive source would you use to treat deep-seated brain tumors-alpha , beta, or…

A: To explain : The type of radioactive source used to treat deep-seated brain tumors

Q: If 250 mg of a radioactive element decays to 220 mg in 36 hours, find the half-life of the element.…

A: Original mass (M) = 250 mg New mass (m) = 220 mg Time taken (t) = 36 hours using radioactive decay…

Q: A Geiger counter reading of a radioactive sample is initially 6520 counts per minute. The same…

A:

Q: Given that radioactive cobalt-60 has a radioactive constant equal to 3.8 x 10° s determine its…

A: Given information: Here, λ is the radioactive constant or decay constant.

Q: An unstable isotope of cobalt, 60Co, has one more neutron in its nucleus than the stable 59Co and is…

A: Given Data The half-life of the isotope is T1/2 = 5.3 years. The mass of the cobalt is m = 4.20×10-2…

Q: A radiation worker stands 10 cm away from a radioactive source of 55 mCi 57Co. Calculate the…

A: It is given that,

Q: A Geiger counter reading of a radioactive sample is initially 7420 counts per minute. The same…

A:

Q: The graph represents the activity of a sample with respect to time of a radioactive nuclide.…

A: The activity (A) of a radioactive sample is defined as the number of disintegrations per second. The…

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: A substance decays according to the formula Q = 24(0.5)"2.4, where t is in weeks. (a) What is its…

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Q: A person is working near a radioactive source and wants to decrease their dose rate by a factor of…

A: The Inverse Square Law - Point sources of x- and gamma radiation follow the inverse square law,…

Q: What isotope is produced when Np-239 emits a beta particle?

A:

Q: A sample of plutonium-239 has a mass of 24.0 mg. If after 72300 years 6.00mg are left, what is the…

A: Given data:  Initial quantity of plutonium (N0) = 24.0 mg Time elapsed (t) = 72300 years  Remaining…

Q: If the half-life of a radioisotope is 2 days, after how many days is the quantity reduced to 12.5%…

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Q: A dose of 8.60 mCi of a radioactive isotope is injected into a patient. The isotope has a half-life…

A:

Half Life

The concept of Half Life has numerous practical applications some of them includes figuring out the effective drug dosage to finding out when a radioactive becomes safe to use. If you look for a career in Nuclear Physics you will need this concept.