Many transuranium elements, such as plutonium-232, have very short half-lives. (For ²³²Pu, the half-life is 36 minutes.) However, some, like protactinium-231 (half-life = 3.34 × 10⁴  years), have relatively long half-lives. Use the masses given in the following table to calculate the change in energy when 1 mole of ²³²Pu nuclei and 1 mole of ²³¹Pa nuclei are each formed from their respective number of protons and neutrons.

(Since the masses of ²³²Pu and ²³¹Pa are atomic masses, they each include the mass of the electrons present. The mass of the nucleus will be the atomic mass minus the mass of the electrons.)

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Atom or Neutron Proton Electron 232Pu 231Pa Particle Atomic Mass 1.67493 x 10-24 g 1.67262 x 10-24 g 9.10939 X 10-28 g 3.85285 x 10-22 g 3.83616 x 10-22 g