@lolzy by basic physics energy can't be created or destroyed, but by nuclear physics it can.In nuclear reactions a tiny portion of the matter is converted to energy, u know, like in e = m c to the second.
@Jallibad Not a single bit of energy is created in nuclear physics. E=mc^2 is an equation, meaning that it is equal and solvable.
In a nuclear reaction, the entire atom, when split, is converted to energy. In nuclear explosions though, not all of the matter is split, only a small fraction is. This is why there is nuclear fallout. If every atom was split, there would be no nuclear radiation after a nuclear blast.