Problem 71
Plutonium- 241 undergoes a 13-step decay series. If an alpha particle is emitted in the first step, what is the daughter product?
Problem 72
Plutonium- 241 undergoes a 13-step decay series. If an alpha particle is emitted in the first step followed by a beta particle, what is the granddaughter product?
Problem 73
Plutonium- 241 undergoes a 13-step decay series. If an alpha particle is emitted in the first step, what is the daughter product?
Problem 74
Nuclide \(X\) has a half-life of 2.6 years and decays by electron capture to produce \(\mathrm{Mn}-55\) and a gamma ray. Write a nuclear equation for the reaction.
Problem 75
Crater Lake in Oregon was formed by volcanic explosion. If a tree charred by the explosion gave an activity of \(\sim 7.7 \mathrm{dpm}\) and the half-life of \(\mathrm{C}-14\) is 5730 years, what is the approximate age of Crater Lake?
Problem 76
Uranium-lead dating of lunar rock samples gave a U-238 to \(\mathrm{Pb}-206\) ratio of \(\sim 1.0 .\) If the half-life of \(\mathrm{U}-238\) is 4.5 billion years, what is the approximate age of the lunar rocks?
Problem 77
A radionuclide ionizes the air in a smoke detector, which in turn allows the flow of electricity. When smoke particles enter the detector, they disrupt the electric current and set off an alarm. What \(\alpha\) -emitting radionuclide is used to ionize the air in a smoke detector? (Hint: The radionuclide decays into \(\mathrm{Np}-237 .)\)
Problem 78
A PET scan is a medical imaging technique for the circulatory system. First, a radionuclide is injected that decays by positron emission. When the positron is emitted, it strikes an electron, causing mutual annihilation and the release of two gamma rays. Write an equation for the annihilation reaction.
Problem 79
Element 99 was first synthesized by bombarding uranium- 238 with neutrons. The reaction yielded Es- 253 and seven beta particles. How many neutrons are necessary to balance the equation?
Problem 80
Element 100 was first synthesized by bombarding uranium-238 with neutrons. The reaction yielded Fm-255 and eight beta particles. How many neutrons are necessary to balance the equation?
