A radioactive element has a half-life of 3 days. The initial amount of that element is 1024 grams. How many grams of that element are left 12 days later? Write down your answer as an integer value (no decimals) and do not write the unit.
Q: A 416 g sample of sodium-24 decays to 13.0 g of sodium-24 within 60.0 hours. What is the half-life…
A: Given data: The initial quantity is N0=416 g. Quantity after decay is N(t)=13.0 g. Time elapsed is…
Q: The half life of an unknown substance is 1 week. How much of its nuclei were disintegrated after 10…
A:
Q: If you are told the half life of a material is 3,500 years, then how much would be remaining from a…
A: Given data: Half life (t1/2)= 3,500 years Initial quantity of the substance (N0) = 10 g Time elapsed…
Q: The half-life of Carbon-14 is 7 years. How much of an initial 168 g sample will remain after 30…
A:
Q: hat atomic number, mass number, and element results when a Radon-222 atom emits a gamma ray through…
A: As we know that the atomic number of Radon is 86 and mass number is 222.
Q: If a material has a half life of 92.5 days, how long will it take for 75% of the material to decay?…
A: Half life of the material=92.5days 75% of the material decay
Q: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…
A: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…
Q: Q6: 100 g of radioactive element X are placed in a sealed box. The half-life of this isotope of X is…
A: Disclaimer: Since you have posted two questions and no specific question number is mentioned, we…
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: A particular isotope has a half-life of 1 minute. If you start with 1 gram of this isotope, how much…
A: In the given question, We have to determine the remaining quantity of the isotope after 10 minute.
Q: The half-life of a radioactive material whose rate of disintegration is proportional to the amount…
A: The half-life of a radioactive element is defined as the time required to decrease the initial…
Q: What mass of a 2,400g sample of an isotope will remain after 32.8 days if the half life of the…
A: Hello. Since you have posted multiple questions and not specified which question needs to be solved,…
Q: A sample containing 1 gram of Radium-224 was stored in laboratory 100 years ago. Now the sample…
A: Given data: The mass of Radium-224 at 100 years ago is m0=1 g. The mass of Radium-224 at now is…
Q: Which radioactive isotopes are produced when Uranium 238 decays?
A: When uranium 238 decays, it decay by emitting alpha particle.
Q: Certain radioactive substances has a half-life of 20 min. If there is 56 lbs of it right now, how…
A:
Q: A radioactive material has a half-life of eight days. How long will it take for the material to be…
A:
Q: The isotope cesium-137 has a half-life of 29.75 years. How long will it take a 100 gram sample of…
A: Given data The half-life of the cesium-137 is t1/2 = 29.75 years. The initial amount of the…
Q: Thirty percent of a radioactive substance decays in two years. By what percent does the substance…
A:
Q: A sample of polonium-208 has a half-life of 2.898 years. What percent of polonium-208 remains after…
A: The half-life of a radioactive substance is the time required for a quantity to reduce to half of…
Q: If carbon-14 underwent beta decay, what is the resulting nucleus?
A: Beta decay: A element which undergoes beta decay then the neutron of the atom gets converted to…
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: A radioactive substance plutonium-239 has a half-life of 24,000 years. Initially, there is 700 mg of…
A:
Q: A sample of Uranium ore is estimated to have originally contained 805 mg of uranium-238. Analysis…
A: “Since you have asked multiple questions, we will solve the first question for you. If you want any…
Q: What is the half-life of a radioactive isotope if the activity of a sample drops from 14,080 cpm to…
A:
Q: What happens when one kilogram of uranium undergoes nuclear fission?
A: to find : what happens when 1 kg of Uranium undergoes nuclear fission
Q: how much energy (in Joules) is released by Helium -4 during a nuclear reaction?
A: Given: Helium-4 Asked to find energy released during a nuclear reaction.
Q: f the half-life of cesium-137 is 30 years, approximately how much time will be required to reduce a…
A:
Q: If the half-life of an isotope is two years, what fraction of the isotope remains after six years
A: Amount of radioactive material after time t is given by: N = N0*exp(-lambda*t) lambda = decay…
Q: A radioactive isotope has a half-life of 51.5 days. What fraction of the isotope remains after 413…
A: We have: The half-life is t1/2=51.5 days Calculating the first-order reaction constant k as…
Q: The half-life of Uranium-237 is 5.83 x 105 If you have a sample with 5.89 x 1024 atoms in it, how…
A:
Q: The half-life of a particular radioactive isotope is 6.5 h. If there are initially 48 * 1019 atoms…
A: Given: Half life of isotope, T = 6.5 hours Initial number of atoms, No = 48 x 1019 atoms Total…
Q: If a sample of a radioactive isotope has a half-life of 3 years, how much of the original sample…
A: The half-life of the sample = 3 years (a) That means, after every 3year the sample becomes half of…
Q: Radium-226, the first radioactive isotope used for its radioactive properties, has a half life of…
A: Radium-226 has a half-life, T12=23.0 centuries. The value of the rate constant is given by: λ=ln2T12…
Q: The half-life of a radioactive isotope is 140 d. How many days would it take for the decay rate of a…
A: Given: Half life of the isotope, T = 140 days
Q: Carbon 14, with a half-life of 5700 years, is used to estimate the age of organic materials. What…
A: The expression for the half-life of carbon-14 is written as, Here, λ represents the decay constant…
Q: A radioactive nuclide has a half-life of 10 seconds. Beginning with 256 grams of the material, how…
A: Given: Half life period t1/2 = 10 sec Initial concentration N0 = 256 g Time = 1 min = 60 sec = 6…
Q: You are experimenting with a radioactive sample of polonium. At the end of 14.0 minutes, exactly…
A:
Q: The half-life of the radioactive element unobtanium-53 is 5 seconds. If 176 grams of unobtanium-53…
A:
Q: If a 1.50-cm-thick piece of lead can absorb 90.0% of the γ rays from a radioactive source, how many…
A: Given data The thickness of the lead piece is x = 1.50 cm. Lead can absorb 90% of the γ rays.…
Q: Technetium-99m is a radioactive isotope with a half-life of 6 hours. If a sample of was originally…
A:
Q: the half-life of Uranium-238 is 4.46 × 109 years. If a sample of mass 10kg is thought to have formed…
A:
Q: A radioactive isotope of silver has half-life of 20 minutes. What fraction of the original mass…
A:
Step by step
Solved in 2 steps with 1 images
- An accident at a nuclear power plant has left the surrounding area polluted with radioactive material that decays naturally. The initial amount of radioactive material present is 42 su (safe units), and 5 months later it is still 31 su. a.) write a formula giving the amount A(t) of radioactive material (in su) remaining after t months. (Use integers or decimals for any numbers in the expression. Round to three decimal places needed.) b.) what amount of radioactive material will remain after 11 months? c.) how long will it be until A = 1 su, so it is safe for people to return to the area?A sample of a radioactive substance has an initial mass of 63.3 mg. This substance follows a continuous exponential decay model and has a half-life of 5 days. (a) Let t be the time (in days) since the start of the experiment, and let y be the amount of the substance at time t. Olno Write a formula relating y to t. Use exact expressions to fill in the missing parts of the formula. Do not use approximations. y = (b) How much will be present in 13 days? Do not round any intermediate computations, and round your answer to the nearest tenth. O mg I Don't Know Submit O2021 McGraw Hill LLC. All Rights Reserved. Terms of Use I Privacy Center | Accessibility MacBook Ai F11 80 888 F10 FB F9 F7 F6 esc F3 F4 F5 F2 $ 8 9 * 00An unknown radioactive element decays into non-radioactive substances. In 360 days the radioactivity of a sample decreases by 34 percent. (a) Find the decay constant k. (Round your answer to 5 decimal places.) (b) What is the half-life of the element? (Round your answer to two decimal places) half-life: (days) (c) How long will it take for a sample of 100 mg to decay to 59 mg? (Round your answer to two decimal places) time needed: (days)
- A radioactive material disintegrate at such a rate that after 3.4 seconds, only 79% of the original substance is left. What is the half-life of the material, expressed in seconds (keep three significant digits)?RADIOACTIVITY. LAW OF RADIOACTIVE DECAY Activity units: 1 Ci = 3.7 × 101º Bq 1. Nuclear decay law: N = Noe¬at, The law of radioactive decay gives the quantitative relationship between the original number of nuclei present at time zero No and the number N at a later time t (sec), where e = 2.71828... is the base of the natural logarithm, and 2 is the decay constant for the nuclide (1/s). 2. Relationship between decay constant 2 and isotop half-life T1/2: In(2) 0.693 Radioisotope Half-life Modality T1/2 T1/2 Carbon-11 20 minutes PET where a is decay constant (1/s), T1/2 is isotope half- life (s). 3. Activity or decay rate of a radioactive source A: ΔΝ Fluorine-18 110 minutes PET Copper-64 12.7 hours PET Gallium-67 78.3 hours SPECT Gallium-68 68 minutes PET = AN Technetum-99m 6.02 hours SPECT Δt where A is activity or decay rate of a radioactive source (Bq), N is number of nuclei present at time t (s ), 1 is decay constant (1/s). 4. Activity A of a radioactive source at a time t:…RADIOACTIVITY. LAW OF RADIOACTIVE DECAY Activity units: 1 Ci = 3.7 × 1010 Bq 1. Nuclear decay law: N = Noe¬at, The law of radioactive decay gives the quantitative relationship between the original number of nuclei present at time zero No and the number N at a later time t (sec), where e = 2.71828... is the base of the natural logarithm, and 2 is the decay constant for the nuclide (1/s). 2. Relationship between decay constant 1 and isotop half-life T1/2: 0.693 T1/2 1= In(2) Half-life Modality Radioisotope T1/2 where a is decay constant (1/s), T1/2 is isotope half- life (s). Carbon-11 20 minutes PET Fluorine-18 110 minutes PET Copper-64 | 12.7 hours PET 3. Activity or decay rate of a radioactive source A: Gallium-67 AN A = At where A is activity or decay rate of a radioactive lodine-123 source (Bq), N is number of nuclei present at time t Thallium-201 (s ), 2 is decay constant (1/s). 78.3 hours SPECT | 68 minutes Gallium-68 Technetum-99m PET 6.02 hours SPECT Indium-111 | 67.3 hours SPECT…
- 20.0 hours after being ingested 74.5 % of the original radioactive atoms have decayed or been eliminated. If the biological half-life is known to be 35.0 hours, what is the physical half-life of this isotope? State the time in hours to 1 decimal places but do NOT include units in your answer. Your Answer:1. The half-life of a radioactive substance is the time it takes for half of the substance to decay. The radioactive iodine isotope I-131, which has a half-life of 8 days, is used to treat hyperthyroidism. Solve 400 - 3.125 to find how many days t it will take for 400 millicuries of I-131 to decay to 3.125 millicuries. A 56 days в 7days C 8 days D 128 days 2. In the year 2000, the population of Mexico was about 100 million, and was growing by approximately 1.53% per year. At this growth rate, the function Ax) = 100(1.0153)* gives the population, in millions, x years after 2000. Using this model and a graph of the function, in what year would the population reach 109 million? Round your answer to the nearest year. 2006 C 2005 D 2007 A в 2008 3. Use a graph to solve 3* - 100. A x-4.2 в х-2.1 C x- 0.2 D x-0.1Problem 9: Answer the following questions based on the graph of a radioactive iodine isotope shown to the right. Part (a) What is the half-life of the material in days? t = _________ days Part (b) In how many days does the substance decay to one-fourth its original value? t = _________ days
- The half-life of phosphorus-32 is about 14days. There are 6.6 grams present initially.a. Express the amount of phosphorus-32 remaining as a function of time t.b. When will there be 1 gram remaining?Phosphorus-32 is a commonly used radioactive nuclide in biochemical research, particularly in studies of nucleic acids. The half-life of phosphorus-32 is 14.3 days. What mass of phosphorus-32, in milligrams, is left from an original sample of 175 mg of Na "PO, after 38.8 days? Assume that the atomic mass of 32P is 32.0.A certain radioactive material decays exponentially. The percent, P, of the material left after t years is given by P(t) = 100(1.2). a. Determine the half-life of the substance. b. How fast is the substance decaying at the point where the half-life is reached? The substance is decaying at a rate of about -3.8% per year at the time 9.12 years where the half-life is reached The substance is decaying at a rate of about -9.12% per year at the time 6.8 years where the half-life is reached The substance is decaying at a rate of about -9.12% per year at the time 3.8 years where the half-life is reached | None of the above