A biologist has a 6894-gram sample of a radioactive substance. Find the mass of the sample after two hours if it decreases according to a continuous exponential decay model, at a relative rate of 9% per hour. Do not round any intermediate computations, and round your answer to the nearest tenth. grams

A biologist has a 6894-gram sample of a radioactive substance. Find the mass of the sample after two hours if it decreases according to a continuous exponential decay model, at a relative rate of 9% per hour. Do not round any intermediate computations, and round your answer to the nearest tenth. grams

College Physics

10th Edition

ISBN:9781285737027

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter30: Nuclear Energy And Elementary Particles

Section: Chapter Questions

Problem 12P

See similar textbooks

Similar questions

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 * 00
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 radioactive substance decays according to the following function, where y, is the initial amount present, and y is the amount present at timet (in days). -0.072 t y=yoe Find the half-life of this substance. Do not round any intermediate computations, and round your answer to the nearest tenth. | days
Measurements of a certain isotope tell you that the decay rate decreases from 8322 decays/minute to 3162 decays/minute over a period of 4.50 days K ▼ Part A What is the half-life T1/2 of this isotope? Express your answer numerically, in days, to three significant figures. ► View Available Hint(s) —| ΑΣΦΑΛΟ T1/2 = Submit Provide Feedback t O ? days
Problem B The decay rate of a radioactive source decreases by 69.7% in 97 h. Determine the half-life, decay constant, & mean life of the source. T1/2= λ = T = h-1
At the beginning of an experiment, a scientist has 252 grams of radioactive goo. After 195 minutes, her sample has decayed to 3.9375 grams. What is the half-life of the goo in minutes? Find a formula for G(t), the amount of goo remaining at time t. G(t) || How many grams of goo will remain after 32 minutes?
QUESTION 13 The following table of probabilistic time estimates (in weeks) and activity predecessors are provided for a project Immediate Most Probable Predecessor Activity A B C D E F G H Table 1 Reference: Ref 1 A, B B C D, E F Optimistic Time Time 11 13 5 13 6 3 4 6 2 3 10 5 6 8 4 13 Using Table 1, the earliest start time for activity G is OA. 0.0 weeks. OB. 10.0 weeks. O C. 10.5 weeks. O D. 15.5 weeks. O E. None of the above Pessimistic Time 14 19 14 7 11 13 6 9 decessors are p
There was a sample of 500 milligrams of a radioactive substance to start a study. Since then, the sample has decayed by 2.6% each year. Let & be the number of years since the start of the study. Let y be the mass of the sample in milligrams. Write an exponential function showing the relationship between y and t.
An 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)
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…
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:…
Density is the ratio of mass to volume. If a uranium nucleus has a radius of 7.4 femtometers and nuclear mass of 238 AMU, what is its density in kg/m3? Assume the nucleus is sphere-shaped to find its volume.