When a nucleus is split, what form of energy is released? When an nucleus is split, what form of energy is released? All of the websites I have looked at say there is a lot of energy released when an atom is split, but it never says what form of energy it is in. Is it electrical energy, or is it just a lot of heat, or something else?
 A: The energy that is released when a the absorption of a neutron causes a heavy atom nucleus to fission into two daughter nuclei comes from the tighter binding energy of the two daughter nuclei compared to the weaker (smaller) binding energy of the original nucleus.  
This extra energy is mostly released in the form of the kinetic energy of the two daughter nuclei.  Therefore most of the energy is released as the equivalent of heat energy.
A: The mass of an atom is always less than the sum of the masses of the particles that compose it. The lack of mass (or energy, from E = mc^2) is called binding energy and it is the energy expended by the particles to remain confined inside of the atom. When fission occurs, not more spending of energy to hold together the individual particles. So the energy that is released corresponds to the binding energy and it is distributed among the fission products in the form of kinetic energy.
A: A lot of different forms, but mostly kinetic energy.
A good table is given at Hyperphysics. The energy released from fission of uranium-235 is about 215 MeV. This is divided into:

*

*Kinetic energy of fragments (heat): ~168 MeV

*Assorted gamma rays: ~15-24 MeV

*Beta particles (electrons/positrons) and their kinetic energy: ~8 MeV

*Assorted neutrons and their kinetic energy: ~17 MeV

*Neutrinos and their kinetic energy: ~?

Note that neutrons can, if left alone for long enough, decay, typically by this reaction:
$$\text{n} \to \text{p} + \bar{\text{v}}_{\text{e}} + \text{e}^{-}$$
where $\text{n}$, $\text{p}$, $\bar{\text{v}}_{\text{e}}$, and $\text{e}^{-}$ represent neutrons, protons, anti-electron neutrinos, and electrons, respectively.
