a certain radioactive substance decays at a rate proportional to the amount present. If a quarter of it decayed after 35 hours , find the half-life of a substance in number of days

Q: The R & D department of the company is testing whether radioactive materials can be used as fuels in…

A: We know for radio active decay it follows first order rate equation. So we have to use the first…

Q: Suppose the amount of a certain radioactive substance in a sample decays from 4.60 mg to 1.90 mg…

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Q: Substance D initially weights 56 grams. After 6 minutes, it was observed that its mass decreased by…

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Q: The​ half-life of a radioactive substance is 50 years. If you start with some amount of this​…

A: Suppose we start with 1 gram of the sample. Therefore--- Initial amount (N0) = 1 g The half-life…

Q: Sodium-24, which is used to locate blood clots in the human circulatory system, has a half-life of…

A: Half life period: The time required to decay half of the initial amount is known as half life…

Q: Suppose the amount of a certain radioactive substance in a sample decays from 8.50 mg to 3.80 mg…

A: Given Initial concentration of radioactive substance =          8.50mg Final concentration of…

Q: The isotope nickel-63 has a half-life of 100 years. If a tested sample has five grams of nickel-63…

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Q: Answer  4460 years

A: Expression for half-life period of radioactive element is given as,

Q: Radioactive calcium-47 decays with a half-life of 4.5 days. A chemist obtains a fresh sample of…

A: Half life of sample T = 4.5 days Final radioactivity A' = (100-25) % of A = 75 % of A.  A is initial…

Q: An unknown radioisotope exhibits 8540 decays per second.After 350.0 min, the number of decays…

A: Nuclear reactions are a type of chemical process which lead to the formation of some new nuclei with…

Q: A radioactive substance decays at a rate proportional to the amount present. If 45 percent of a…

A: Given :   Time (t) = 20 years  Percentage of substance decays = 45 %

Q: A sample of sodium thiosulfate, Na2S2O3, contains sulfur-35. Determine the mass of in the sample…

A: Given, Half life of sodium thiosulfate = 88 days

Q: Given the rate constant, k, for the decay of a radioactive substance, how would you find the…

A: Given :- rate constant for decay of radioactive substance = k  To find :- half-life (t1/2)

Q: Approximately how many half-lives must pass for the amount of radioactivity in a substance to…

A: Given, radioactivity of the substance decreases below 1% of its initial level.The initial percentage…

Q: (19] There are 40 grams of radioactive substance at one point in time. After two hours, only 30…

A: The half-life of a quantity is the amount of time it takes to decrease to half of its original…

Q: If 7.0 grams of a sample decays to 0.44 grams in 2.0 hours, what is the half-life time of the…

A: For calculation of half life first of all we need rate constant of the reaction, which can be…

Q: If half-life of carbon-14 is 5730 years, estimate the age of a bone containing 75% of its original…

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Q: In a sample of a radioactive isotope, 20.0 % has decayed after 30.0 days. Calculate the half-life of…

A: The nuclear reactions are a type of chemical processes which lead to the formation of some new…

Q: A sample has a half life of 100 years. If it has been 200 years since it started to decay and there…

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Q: Suppose the amount of a certain radioactive substance in a sample decays from 7.10 mg to 5.20 mg…

A: Radioactive decays are first order reactions. Since we know that the relationship between the amount…

Q: If a tree dies and the trunk remains undisturbed for 1.895 × 10ª years, what percentage of the…

A: Mass% is equal to the ratio of the mass of the given substance to the total mass of the substance.…

Q: Suppose the amount of a certain radioactive substance in a sample decays from 6.50 mg to 2.40 mg…

A: Radioactive decay is a first-order reaction. On applying the value for rate constant k, we find it…

Q: what fraction of a radioisotope has decayed after two half-lives?

A: The time required for a quantity of a radioisotope to decay by half is known as the half-life time.…

Q: The​ half-life of​ silicon-32 is 710 years. If 20 grams is present​ now, how much will be present…

A: Radioactive decay is always a first order reaction. The rate equation for the radioactive decay is :…

Q: The half-life of radioactive chromium-51 is 28 days. If a sample of chromium-51 has a mass of 12.0…

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Q: Suppose the amount of a certain radioactive substance in a sample decays from 7.40 mg to 4.60 mg…

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Q: If a tree dies and the trunk remains undisturbed for 1.775 × 10⁴ years, what percentage of the…

A: Given-> Half life = 5730 year  Time = 1.775 × 104 year.

Q: The half-life of radiogold is approximately 3 days. If 1.5 g of this has been administered to a…

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Q: The half life of the radioactive element ubtonium-31 is 10 seconds. If 80 grams of unobtanium-31 are…

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Q: Phosphorus-32 is a radioisotope used to detect certain types of tumors. P-32 has an effective…

A: Phosphorus-32 is a radioisotope used to detect certain types of tumours. P-32 has an effective…

Q: The half-life of Palladium-100 is 4 days. After 12 days a sample of Palladium-100 has been reduced…

A: The initial mass of the sample of palladium-100, No, in mg is calculated as shown below where t1/2…

Q: original

A: t1/2 =  8.02 days t = ? for 99% decay

Q: A rock is analyzed in the laboratory for radiometric dating and found to contain 1/8 parent atoms…

A: Any process that occurs by radioactive decay follows first-order kinetics. The equation used to…

Q: If a tree dies and the trunk remains undisturbed for 1.170 × 10' years, what percentage of the…

A: This is a first order reaction. t½ = 0.693 ÷ k 5730 = 0.693 ÷ k k = 1.21 × 10-4  year-1 where k is…

Q: A certain substance is known to decay at a rate proportional to the present amount. Initially, there…

A: Radioactive decay is the first order reaction.The half life time for a radioactivedecay is given by…

Q: Carbon-14 dating is used to find the age of ancient objects. The half-life of Carbon-14 is 5730…

A: Given : Half life of Carbon-14 = 5730 years  And the piece of clay pot has undergone 1.5 half lives.…

Q: The half-life of Palladium-100 is 4 days. After 20 days a sample of Palladium-100 has been reduced…

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Q: unknown sample contains radioactive element U-235. If the original amount present is 3500 atoms, how…

A: Given- Number of initial atom =3500 atoms Number of final atom =125 atoms  Half life =700 million…

Q: If a tree dies and the trunk remains undisturbed for 1.620 x 104 what percentage of the original 1*C…

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Q: One of the radioactive isotopes used in medical treatment or analysis is iodine-125. The half-life…

A: radio active decay are first order                       Rate constant =0.693/half life…

Q: Radioactive phosphorus-32 decays with a half-life of 14.0 days. A chemist obtains a fresh sample of…

A: We have to calculate the number of days chemist have to do the experiment.

Q: An archaeologist finds some ancient jewelry made from bone. The jewelry has a carbon mass of 484 g…

A: Nuclear decay follows 1st order reaction.  Given the half-life of C-14, t1/2 = 5730 year…

Q: The half-life of radioactive strontium-90 is 28.8 years. How long would it take when only 16.5% of…

A: The half-life of strontium-90 is = 28.8 years Time would it take when only 16.5% of the original…

Q: If a tree dies and the trunk remains undisturbed for 1.635 × 10⁴ years, what percentage of the…

A: Given, time t = 1.6 x 104 years , half life t1/2 = 5730 years

Q: If 1.50 gram of a 2.00 gram sample of a radioactive substance undergoes decay in 60 minutes, then…

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Q: The half-life of tritium, H-3, is 12.3 years. How much time would it take for a sample to drop to…

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Q: The half life of radium-226, the first radioactive element discovered, is 1,620 years. If a sample…

A: Radioactive reactions are of first order. The relationship between half life t1/2 and rate constant…

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…