(a)
Interpretation:
The total counting rate for sample is 450cpm (sample plus background) and the counting period for this rate is 15.0min. The counting rate for background is 7 cpm for time period 2.0 min. The value of corrected counting rate is to be determined.
Concept introduction:
The following formula will be used for the corrected counting rate-
Where,
(b)
Interpretation:
The total counting rate for sample is 450cpm (sample plus background) and the counting period for this rate is 15.0min. The counting rate for the background is 7 cpm for time period 2.0 min. The value of standard deviation
Concept introduction:
The formula used for the calculation of standard deviation for the corrected counting rate is-
Where,
(c)
Interpretation:
The total counting rate for sample is 450cpm (sample plus background) and the counting period for this rate is 15.0min. The counting rate for background is 7 cpm for time period 2.0 min. The value of 95% confidence interval for the corrected counting rate is to be determined.
Concept introduction:
The formula that will be used-
The formula used for the calculation of standard deviation for the corrected counting rate is-
Where,
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Chapter 32 Solutions
Principles of Instrumental Analysis, 6th Edition
- Strontium-90 is a radioactive material that decays according to the function A(t)=A0e−0.0244t, where A0 is the initial amount present and A is the amount present at time t (in years). Assume that a scientist has a sample of 500 grams ofstrontium-90. (a) What is the decay rate of strontium-90? (b) How much strontium-90 is left after 40years? (c) When will only 300 grams of strontium-90 be left? (d) What is the half-life of strontium-90?arrow_forwardFor intitial radioactivity, 1 is the highest and 4 is the lowestarrow_forwardSince the radioactivity defined as 1 Ci for 1,00 grams of 226Ra released by 42He2+≡ a(equivalent) particles is 3.7 * 1010 Bq; Find the fragmentation rate constant, the half-time and the fragmentation rate after 999 years.arrow_forward
- Radioactive decay The radioactive bismuth isotope 21°BI has a half-life of 5 days. If there is 100 milligrams of 210Bi present at t = 0, then the amount f(t) remaining after t days is given by f(t) = 100(2) 5. (a) How much 210BI remains after 5 days? 10 days? 12.5 days? (b) Sketch the graph of f for 0 sts 30.arrow_forwardA 0.0100 g sample of a radioactive isotope with a half-life (to.s) of 1.3-10° yr decays at the rate of 2.9-10* disintegrations per minute (dpm). Calculate i) decay constant (1) (in unit min-1) ii) number of nuclei (N)| iii) molar mass (M) of the isotope.arrow_forwardThe half-life of a decaying radioactive isotope is the time it takes for half of the original mass of the isotope to decay. M (t) If the mass (in grams) of a particular radioactive sample is given by 20e-0.32t = where t is in years, what is the half-life of that isotope? Round your answer to 2 decimal places. Do not include units. √0 €∞o αΩ [bg] {g DB I felim √0 (0) [0] 1 € Ø∞ CUN TU %90 4 0 (0) ㅁㅁ 8 + H X AI VI + î OParrow_forward
- In the present geological period rubidium contains 27 wt % 87Rb, which is a 3 emitter with a decay constant of 1.1 x 10-11 y-¹. In 30 g of the mineral pollucite from Varuträsk in northern Sweden, 450 mg Rb and 0.90 mg Sr was found on analysis. It was shown with a mass spectrometer that 80% of this Sr was 87 Sr, which had presumably been formed from Rb. Calculate the age of the mineral in years.arrow_forward28Mg lies above the band of stability- its most likely mode of decay is what? For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac).arrow_forwardWhat is the process of elution in extracting Ba-137 from the Isotope Generator (2-3 sentences would doarrow_forward
- An atomic isotope radioactively decays and has a half-life of 23.7 days. How many days will it take for 88.2% of the sample to decay? In([A]MA]) = -kt t1/2 = (In2/k) 券 (1/[A]) = kt + (1/AI,) t1/2 (1/k[A],) [A]=-kt + [Alo t1/2 = ([A]/2k) In(k2/kq) = (E/R)[(1/T;)- (1/T2)] R= 0.0820573L atm/(K mol) उस R = 8.31446 J 7(K mol) Type your answer in the space below without the units.arrow_forward6. Iridium is a radioactive elementused fortherapy in nucle arme dicine. It decaysto% or 21, of its original mass after 74 days. After148 days, it de caysto %, or 2:2, of its original mass. a) what fraction remains after 222 days? Write fraction as a powerof 2 with a ne gative exponentalso. b) What fraction remains after 370 days? Write fraction as a powerof 2 with a ne gative exponentalso.arrow_forward* 87%| 1 PM Thu Nov 12 A webassign.net This exercise uses the radioactive decay model. The half-life of radium-226 is 1600 years. Suppose we have a 22-mg sample. (a) Find a function m(t) = mo2-t/h that models the mass remaining after t years. m(t) = (b) Find a function m(t) = moe¯rt that models the mass remaining after t years. (Round your r value to six decimal places.) m(t) = (c) How much of the sample will remain after 4500 years? (Round your answer to one decimal place.) mg (d) After how many years will only 15 mg of the sample remain? (Round your answer to one decimal place.) yrarrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning
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