Back
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. a. Mg-26 b. Ne-25 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 c. P-27 d. Sn-100
Problem 42a
Predict a likely mode of decay for each unstable nuclide. a. Sb-132 b. Te-139 d. Ba-123
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 b. Fe-45 or Fe-52
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 46
A patient is given 0.050 mg of technetium-99m, a radioactive isotope with a half-life of about 6.0 hours. How long does it take for the radioactive isotope to decay to 1.0⨉10-3 mg? (Assume no excretion of the nuclide from the body.)
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.)
- A wooden boat discovered just south of the Great Pyramid in Egypt has a carbon-14 to carbon-12 ratio that is 72.5% of that found in living organisms. How old is the boat?
Problem 51
- A layer of peat beneath the glacial sediments of the last ice age has a carbon-14 to carbon-12 ratio that is 22.8% of that found in living organisms. How long ago was this ice age?
Problem 52
- An ancient skull has a carbon-14 decay rate of 0.85 disintegrations per minute per gram of carbon (0.85 dis/min/g C). How old is the skull? (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 years.)
Problem 53
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 55
A rock from Australia contains 0.438 g of Pb-206 for every 1.00 g of U-238. Assuming that the rock did not contain any Pb-206 at the time of its formation, how old is the rock?
- A meteor has a Pb-206:U-238 mass ratio of 0.855:1.00. What is the age of the meteor? (Assume that the meteor did not contain any Pb-206 at the time of its formation.)
Problem 56
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?
Problem 59
Write the nuclear equation for the fusion of two H-2 atoms to form He-3 and one neutron.
Problem 60
Write the nuclear equation for the fusion of H-3 with H-1 to form He-4.
- A breeder nuclear reactor is a reactor in which nonfissionable (nonfissile) U-238 is converted into fissionable (fissile) Pu-239. The process involves bombardment of U-238 by neutrons to form U-239, which then undergoes two sequential beta decays. Write nuclear equations for this process.
Problem 61
- Is the series of nuclear equations to represent the bombardment of Al-27 with a neutron to form a product that subsequently undergoes a beta decay written correctly?
Problem 62
Problem 63
Rutherfordium-257 was synthesized by bombarding Cf-249 with C-12. Write the nuclear equation for this reaction.
- Element 107, now named bohrium, was synthesized by German researchers by colliding bismuth-209 with chromium-54 to form a bohrium isotope and one neutron. Write the nuclear equation that represents this reaction.
Problem 64
Problem 65
If 1.0 g of matter is converted to energy, how much energy is formed?
Problem 66
A typical home uses approximately 1.0⨉103 kWh of energy per month. If the energy came from a nuclear reaction, what mass would have to be converted to energy per year to meet the energy needs of the home?