Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Calculate the fraction of each of the following radionuclides that remains after 1 day, 2 days, 3 days, and 4 days (half-lives are given in parentheses): iron-59 (44.51 days), titanium-45 (3.078 h), calcium-47 (4.536 days), and phosphorus-33 (25.3 days).

Short Answer

Expert verified

The fraction of radionuclide which will remain after 1 day, 2 days, 3 days and 4 days:

Step by step solution

01

Given information

For radioactive elements, iron-59, titanium-45, calcium-47, and phosphorous-33, the formula for fraction of sample and half time of sample is used to calculate the fraction of radionuclide that will remain after 1 day, 2 days, 3 days, and 4 days.
02

Concept

The first order of kinetics states:

lnNN0=-λt

Here, Nis final concentration and N0is initial concentrations, λis the decay constant, tand is the passage of time.

localid="1646068104244" t1/2(half-time)=ln2λ

The half-life time is t1/2in this case.

03

Solution

The following formula can be used to compute the sample half-time:

t1/2=ln2λ

The following formula can be used to compute the proportion of sample and time:

lnNN0=-λt

Where,

t1/2=half time

λ=decay constant

NandN0=the number of nuclei that are radioactive.

The radioactive elements' half-lives are stated as
days of iron-59= 44.51

hours of titanium-45= 3.078

days of calcium-47= 4.536

days of phosphorus-33 = 25.3

The above table's spreadsheet documentation is

localid="1646067528747" CellE5=LN(2)/D5

localid="1646067533137" CellBI1=E5*C9*-1

localid="1646067538088" CellC11=EXP(B11)

localid="1646067542914" CellEl1=E5*F9*-1

localid="1646067547700" CellF11=EXP(E11)

localid="1646067552312" CellC18=E5*D16*-1

localid="1646067557274" CellD18=EXP(C18)

localid="1646067562817" CellF18=E5*G16*-1

localid="1646067567937" CellG18=EXP(F18)

The following data will be calculated using the given formulas:

04

Conclusion 

After 1day, 2days, 3days, and 4days, the fraction that remained is -

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) By referring to a reference on NAA or by using an Internet search engine to find the information, describe in some detail the instrumental and radiochemical differences between prompt gamma-ray neutron activation and delayed gamma-ray neutron activation.

(b) What are the types of elements for which prompt gamma-ray activation analysis is most applicable?

(c) Why is delayed gamma-ray emission most often used in NAA?

(d) Why is NAA considered to be a very selective and sensitive method?

(e) A crystal of potassium fluoride is to be studied via NAA. The following table summarizes the behavior of all naturally occurring isotopes in the crystal.

19F, 20Ne, 39K, 41K, and 42Ca are stable, and we will assume that 40K is also stable because it has a half- life of 1.3 * 109 years. What sort of irradiation and detection sequence would you use if you wanted to base your analysis on fluorine?

(f) What sort of irradiation and detection sequence would you use if you wanted to base the analysis on potassium?

(g) Refer to part (e) and calculate the activity due to 20F and 42K in a 58-mg (1.0-millimole) sample of pure potassium fluoride that has been irradiated for 60 s. The thermal neutron cross sections for 19F and 41K

are 0.0090 * 10-24 cm2 and 1.1 * 10-24 cm2 , respectively. Assume a flux density of 1.0 * 10-3 neutrons cm-2s-1.

(h) Find a method in the literature that describes the use of NAA for determining selenium in freshwater ecosystems. Describe the method in detail. Include the neutron source, the irradiation time, and the calculations used. Give the advantages and disadvantages of the method over other analytical techniques.

The penicillin in a mixture was determined by adding 0.981mg of the 14C-labeled compound having a specific activity of 5.42×103cpm/mg. After equilibration, 0.406mgof pure crystalline penicillin was isolated. This material had a net activity of 343cpm. Calculate the mass in milligrams of penicillin in the

sample.

Show, via a calculation, that the average kinetic energy of a population of thermal neutrons is approximately 0.04eV.

A PbSO4sample contains 1 microcurie of Pb-200 (t1/2=21.5 h). What storage period is needed to assure that its activity is less than 0.001 microcurie?

In an isotope dilution experiment, chloride was determined by adding 5.0mgof sodium chloride containing Cl38t1/2=37.3minto a sample. The specific activity of the added NaCl was localid="1646407073099" 3.6×104cps/mg. What was the total amount of chloride present in the original sample if localid="1646407080469" 400mgof pure Agcl was isolated and if this material had a counting rate of localid="1646407089173" 38cpsabove background localid="1646407097779" 150minafter the addition of the radiotracer?

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free