Plutonium-242 decays to uranium-238 by emission of an a particle with an energy of 4.853 MeV. The ²³⁸U that forms is unstable and emits a Υ ray (λ = 0.02757 nm).(b) What would be the energy of the a particle if ²⁴²Pu decayed directly to the more stable ²³⁸U?