Chapter 25, Problem 59EAP

Il One form of nuclear radiation, beta decay, occurs when a neutron changes into a proton, an electron, and a neutral particle called a neutrino: $n\to p^{+}+e^{-}+\nu$ where v 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 ³H, 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: ${}^{3}H{\to }^{3}He+e^{-}+v$

Is charge conserved in the beta decay process? Explain.

b. Why is the final product a helium atom? Explain.

c. The nuclei of both 3H and ³He have radii of 1.5 X 10-15 m.

With what minimum speed must the electron be ejected if it is

to escape from the nucleus and not fall back?