A hypothetical atom with negligible kinetic energy has a mass of 238 amu. It undergoes a beta decay. The remaining atom has atomic mass 237.6 amu. What is the kinetic energy and/or wavelength (whichever is more appropriate) of the emitted particle, assuming that the kinetic energy of the remaining atom is negligible? How much energy would be released by the decay of a mole of these atoms? Note that the mass of a helium nucleus is about 4.001 amu and the mass of an electron about .00055 amu, where an amu is approximately 1.66 * 10^-27 kg?
The change in atomic mass is approximately 238 amu - ( 237.6 amu + .00055 amu) = .3994439 amu, or about .6630769 * 10^-27 kg.
This corresponds to an energy of
A mole of these nuclei would constitute 6.02 * 10^23 nuclei, each releasing 5.967692 * 10^-13 Joules. The total energy released would therefore be