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Problem 20-78a
Complete each nuclear equation and calculate the energy change (in J/mol of reactant) associated with each (Al-27 = 26.981538 amu, Am-241 = 241.056822 amu, He-4 = 4.002603 amu, Np-237 = 237.048166 amu, P-30 = 29.981801 amu, S-32 = 31.972071 amu, and Si-29 = 28.976495 amu).
a. 2713Al + 42He¡3015P + ____
Problem 31a
Write a nuclear equation for the indicated decay of each nuclide. a. U-234 (alpha)
Problem 31c
Write a nuclear equation for the indicated decay of each nuclide. c. Pb-214 (beta)
Problem 31d
Write a nuclear equation for the indicated decay of each nuclide. d. N-13 (positron emission)
Problem 31e
Write a nuclear equation for the indicated decay of each nuclide. e. Cr-51 (electron capture)
Problem 32b
Write a nuclear equation for the indicated decay of each nuclide.
b. Ac-227 (beta)
Problem 32c
Write a nuclear equation for the indicated decay of each nuclide.
c. Tl-207 (beta)
Problem 32d
Write a nuclear equation for the indicated decay of each nuclide.
d. O-15 (positron emission)
Problem 32e
Write a nuclear equation for the indicated decay of each nuclide. e. Pd-103 (electron capture)
Problem 33
Write a partial decay series for Th-232 undergoing the sequential decays: a, b, b, a.
Problem 34
Write a partial decay series for Rn-220 undergoing the sequential decays: a, a, b, b.
Problem 35c
Fill in the missing particles in each nuclear equation. c. 1911Ne → 1910Ne + ____
Problem 36a
Fill in the missing particles in each nuclear equation. a. 24195Am → 23793Np + ____
Problem 36b
Fill in the missing particles in each nuclear equation. b. _____ → 23392U + 0-1e
Problem 36c
Fill in the missing particles in each nuclear equation. c. 23793Np → _____ + 42He
Problem 36d
Fill in the missing particles in each nuclear equation. d. 7535Br → ____ + 0+1e
Problem 37c
Determine whether or not each nuclide is likely to be stable. State your reasons. c. Co-51
Problem 37d
Determine whether or not each nuclide is likely to be stable. State your reasons. d. Te-124
Problem 39
The first six elements of the first transition series have the following number of stable isotopes:
Element Number of Stable Isotopes
Sc 1
Ti 5
V 1
Cr 3
Mn 1
Fe 4
Explain why Sc, V, and Mn each have only one stable isotope while the other elements have several.
Problem 41a
Predict a likely mode of decay for each unstable nuclide. a. Mo-109
Problem 41b
Predict a likely mode of decay for each unstable nuclide. b. Ru-90
Problem 42a
Predict a likely mode of decay for each unstable nuclide. a. Sb-132
Problem 42c
Predict a likely mode of decay for each unstable nuclide. c. Fr-202
Problem 44a
Which nuclide in each pair would you expect to have the longer half-life? a. Cs-149 or Cs-139
Problem 45
One of the nuclides in spent nuclear fuel is U-235, an alpha emitter with a half-life of 703 million years. How long will it take for the amount of U-235 to reach 10.0% of its initial amount?
Problem 47
A radioactive sample contains 1.55 g of an isotope with a halflife of 3.8 days. What mass of the isotope remains after 5.5 days?
Problem 49
A sample of F-18 has an initial decay rate of 1.5⨉105/s. How long will it take for the decay rate to fall to 2.5⨉103/s? (F-18 has a half-life of 1.83 hours.)
Problem 54
A mammoth skeleton has a carbon-14 decay rate of 0.48 disintegration per minute per gram of carbon (0.48 dis/min • g C). When did the mammoth live? (Assume that living organisms have a carbon-14 decay rate of 15.3 dis/min • g C and that carbon- 14 has a half-life of 5715 yr.)
Problem 57
Write the nuclear reaction for the neutron-induced fission of U-235 to form Xe-144 and Sr-90. How many neutrons are produced in the reaction?
Problem 58
Write the nuclear reaction for the neutron-induced fission of U-235 to produce Te-137 and Zr-97. How many neutrons are produced in the reaction?
