what is it's half-life?

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: The half-life of Ga-67 is 77 9 hours. How long will it take Ga-67 to decay and lose 95% of its…

A: Given  Half life of Ga- 67 = 77.9 hours  decay % = 95 %  Time ( t ) = ?

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: A sample of polonium-210 has a half-life of 138 days a)What fraction of polonium-210 remains after…

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Q: The half-life of 238U is 4.5 * 109 yr. A sample of rock of mass 1.6 gproduces 29 dis>s. Assuming…

A: The given data contains, mass = 1.6 g. half life=4.5×109 year.

Q: Age of the Earth. Suppose that at the formation of the Earth there were equal amounts of 235U and…

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Q: After 20 years, only 3.125% of the initial amount of radioactive isotope is left. What is the…

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Q: A moon rock collected by a U.S. Apollo mission is estimated to be 3.70 billion years old by…

A: Since this is a first order decay The rate constant with half life is given by…

Q: A sample of gas from a basement containing radon-222 has an activity of 7 pCi/L, which is above the…

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Q: Plutonium – 236 is an alpha emitter with a half-life of 2.86 years. If a sample initially contains…

A: Given data Half life : t1/2=2.86 year Initial amount : No=2.56 mg time : t=7 year…

Q: What is the half life of a radioactive sample , if 3/4 of its nuclei decay in 2 years ?

A: Given:The amount of nuclear decay in 2 years = ¾ th of initial massAssume that the initial mass =…

Q: A 2.00 gram radioactive substance undergoes decay.  After 60 minutes, 1.50 grams have decayed.  What…

A: Radioactive decay generally follows first-order kinetics and for first-order kinetics:…

Q: 8. How long will it take for a sample of plutonium -239 with a half-life of 24000 years to decay to…

A: Given information : plutonium-239 Half life (t1/2) = 24,000 years Initial amount = Ao Final amount…

Q: 2) If 20.0 g of a radioactive isotope are present at 1:00 PM and 5.0 g remain at 2:00 PM, what is…

A: Since you have asked multiple question, we will solve the first question for you. If you want any…

Q: After 119 days have elapsed, 1/12 of a radioisotope sample remains undecayed. What is the half-life…

A: Amount of radioisotopes remaining = 112 of the initial amount Number of days taken for the decay =…

Q: The half life of an isotope is 43 seconds. How long does it take 100.0g of that isotope to decay to…

A: Half life = 43 second k = 0.693half life= 0.69343 sec=0.016 s-1

Q: Phosphorus-32 has a half-life of 14.0 days. Starting with 6.00 gg of 32P32P, how many grams will…

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Q: How many of the nuclei of a radioactive sample containing 2048nuclei decay in 3 years, if its half…

A: The number of nuclei of a radioactive sample containing 2048 nuclei that decays in 3 years is to be…

Q: The half-life of a certain radioactive element is 800 years. How old is an object if only 12.5% of…

A: Given, Half Life t1/2 = 800 years. A = 12.5%  Ao = 100 %  Time , t = ?

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: The initial amount of thorium-232 in a rock is determined to be 6.78mg. it now has 5.32 mg of…

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Q: A sample of iodine-126 with an original mass of 15.00 mg loses 13.125 mg of the original mass of the…

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Q: A wooden object from a prehistoric site has a carbon-14 activity of 10 counts per minute (CPM)…

A: Given: Half-life = 5730 years [A]=10 cpm [A]0 = 40 cpm

Q: A radioactive waste from a clinical laboratory contains 0.2 µCi (microcuries) of calcium-45 (45Ca)…

A: Answer -

Q: A moon rock collected by a U.S. Apollo mission is estimated to be 3.70 billion years old by…

A: Calculate the value of rate constant (k):

Q: The half-life of a radioactive isotope is 12.8 seconds. Starting with 0.960 g of this isotope, how…

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Q: The half-life of radium 226 is 1602 years. If you have 500 grams of radium today how many grams…

A: This is a first order reaction where the radioactive substance disintegrates. The half life time of…

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: 20. At the time an item was produced, 0.01 of the carbon it contained was carbon-14, a radioisotope…

A: Solution

Q: Cobalt-60 is commonly used as a source of beta-particles. How long does it take for 87.5% of a…

A: Radioactive decay is associated with the emission of small energetic particles e.g. beta particles,…

Q: After 19 days have elapsed, 1/21 of a radioisotope sample remains undecayed. What is the half-life…

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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: The radioactive substance neptunium -139 decays to 72.85% of its original amount after 28 hours. How…

A: For radioactive decay, relation between rate constant and its concentration is give below.…

Q: How many of the nuclei of a radioactive sample containing 2048 nuclei decay in 3 years, if it's half…

A: Half life of a radioactive sample is the time in which half of the sample is decayed i.e. 50% of the…

Q: Radium-223 decays with a half-life of 11.4 days. How long will it take for a 0.240 mol sample of…

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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: A moon rock collected by a U.S. Apollo mission is estimated to be 3.50 billion years old by…

A: Given : Time = 3.50 billion years old. Mass of uranium-238 = 1.540g Half life = 4.47 x 109 years

Q: 3.) The Radioactive nuclide co has a half-Life of 8.5 hours, 55 27 what mass of Co Temains from a.…

A: Mass of sample remains after 18 hours is       0.0045 g.

Q: Co-60 is used extensively in radiotherapy as a source of y - rays. Its half-life is 5.27 years. a)…

A: Given, t1/2 = 5.27 years (a) The time required to decrease the activity by 35% of its original value…

Q: an artifiact has a carbon-14 concentration that is 12.5%(1/8th) of that found in living organisms.…

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Q: carbon-14 activity

A: Given data, Basic equation is Ae = Ao x 0.5 (t / t1/2)   Therefore,

Q: what is the half life of an isotope that decays to 25% of its original activity in 68.9 hours?

A: For a first order reaction, rate constant can be calculated as

Q: Cobalt-60, which undergoes beta decay, has a half-life of 5.26 yr. What is the activity of the…

A: The activity of a radioactive sample is measures as `N_0` counts per minute at. The activity of a…

Q: The half-life of Po-214 is 0.001 seconds. How much of a 10 gram sample is left after 0.003 seconds?…

A: We know radioactive decay follows first order reaction kinetics, therefore  t1/2=0.001 s and…

Q: the half life of molybdenum -99 is 67 hr. a 200 ug quantity decays, over time, to 25 ug. how much…

A: Here given, Initial amount (N0) = 200 ug Amount left undisintegrated (N) = 25 ug Half life (t1/2) =…

Q: A rock contains 0.257 mg of lead-206 for every milligram of uranium-238. The half-life for the decay…

A: The first-order rate law can be transformed into another highly useful equation with the decay…

Q: After 119 days have elapsed, 1/21 of a radioisotope sample remains undecayed. What is the half-life…

A: Suppose the initial amount of sample be Ao After 119 days, amount remaining, A = (1/21) Ao The…

Q: How many alpha particles are emitted per minute by a 0.0010-g sample of 238U that has been freshly…

A: Given, Mass of sample = .001 g Half life of uranium = 4.47 x 109 years = 4.47 x 109 x 3.156 x 107…

Q: A wooden artifact from an ancient tomb contains 30 percent of the carbon -14 that is present in…

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Q: One of the nuclides in spent nuclear fuel is U−234U−234, an alpha emitter with a half-life of…

A: Welcome to bartleby !  We have to calculate time (years)