Concept explainers
Interpretation:
The concentration of calcium ions in a sample of milk is to be determined and whether the given sample meets the concentrations, stated on a milk carton or not is to be predicted.
Concept Introduction:
For radioactive elements, the number of disintegrations per second is defined as an activity. Mathematically, it is represented as follows:
The activity is known to be proportional to the number of radioactive nuclei,
Here,
For the change in the number of nuclei per second:
The half-life for a first-order reaction is given as,
Want to see the full answer?
Check out a sample textbook solutionChapter 20 Solutions
MOLECULAR NATURE OF MATTER 7/E LL W/AC
- Fluorine-18 is a radioactive isotope that decays by positron emission to form oxygen-18 with a half-life of 109.7 min. (A positron is a particle with the mass of an electron and a single unit of positive charge; the equation is F918O188+e+10 Physicians use 18F to study the brain by injecting a quantity of ?uoro-substituted glucose into the blood of a patient. The glucose accumulates in the regions where the brain is active and needs nourishment. (a) What is the rate constant for [lie decomposition of ?uorine-18? (b) If a sample of glucose containing radioactive fluorine-18 is injected into the blood, what percent of the radioactivity will remain after 5.59 h? (c) How long does it take for 99.99% of the 18F to decay?arrow_forwardThe isotope S3890r one of the extremely hazardous species in the residues from nuclear power generation. The strontium in a 0.500-g sample diminishes to 0.393 g in 10.0 y. Calculate the half-life.arrow_forwardA chemist studied the reaction mechanism for the reaction 2NO(g)+O2(g)2NO2(g) by reacting N16O with 18O2. If the reaction mechanism is NO+O2NO3(fastequilibrium)NO3+NO2NO2(slow) what distribution of 18O would you expect in the NO2? Assume that N is the central atom in NO3, assume only N16O18O2 forms, and assume stoichiometric amounts of reactants are combined.arrow_forward
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry by OpenStax (2015-05-04)ChemistryISBN:9781938168390Author:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark BlaserPublisher:OpenStaxChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning