One form of nuclear radiation, beta decay, occurs when a

Chapter 25, Problem 25.92

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One form of nuclear radiation, beta decay, occurs when a neutron changes into a proton, an electron, and a neutral particle called a neutrino: n S p+ + e- + n where n is the symbol for a neutrino. When this change happens to a neutron within the nucleus of an atom, the proton remains behind in the nucleus while the electron and neutrino are ejected from the nucleus. The ejected electron is called a beta particle. One nucleus that exhibits beta decay is the isotope of hydrogen 3 H, called tritium, whose nucleus consists of one proton (making it hydrogen) and two neutrons (giving tritium an atomic mass m = 3 u). Tritium is radioactive, and it decays to helium: 3 H S 3 He + e- + n. a. Is charge conserved in the beta decay process? Explain. b. Why is the final product a helium atom? Explain. c. The nuclei of both 3 H and 3 He have radii of 1.5 * 10-15 m. With what minimum speed must the electron be ejected if it is to escape from the nucleus and not fall back?