Atomic particles are often characterized by their kinetic energy in MeV. Alpha decay, or α decay, is a type of radioactive decay inwhich an atomic nucleus emits an α particle and thereby transforms or decays in to an atom with a mass number that is reduced by four and an atomic number that is reduced by two. An α particle is identical to the nucleus of a helium-4 atom, which consists of two protons and two neutrons and has a mass of 6.644 x 10-27kg.( for example uranium-238 decays to form thorium-234) What is the speed of the alpha partic with a 5.0MeV kinetic energy?