Where does the energy from the fusion reaction come from?

Answer 1

It arises from the internal energy of the nucleus, called the binding energy. In the case of light elements, joining two light nuclei to make a heavier one releases energy, because the binding energy changes. In the case of the heavy elements like uranium, splitting the nucleus into two smaller parts also releases energy, for the same reason. In both cases the end result loses a proportion of the initial mass of the nuclei concerned, and this loss of mass equates to the energy released via Einstein's equation E = mc2.

Answer 2

Potential energy, related to the attraction of the strong force. The hydrogen is available since the Big Bang; gradually it is being converted to heavier elements, mainly within stars.

What is happening in the sun is the destruction of some of the mass of the hydrogen nuclei in forming helium, thus releasing energy. (E=mc2).

Answer 3

The equation so often quoted is E=mc2; the energy available in a mass is equal to the mass times the square of the speed of light. Mass has a lot of energy in it. The energy released in a nuclear reaction is equal to the difference in the mass before and after the reaction, times the square of the speed of light.

A nuclear reaction happens when a nuclear particle collides with an atom, or when two atoms collide, in such a way as to produce change at the atomic level. This may produce different particles and atoms, but the combined masses of the products will not have the same mass as the original. The difference is converted into energy.

Consider fusion of a lithium-6 atom and a deuterium atom, resulting in a pair of helium-4 atoms. 6Li has a mass of 6.015 atomic units, 2H has a mass of 2.014 units, and 4He has a mass of 4.0026. So the mass of the 6Li and 2H atoms combines to 8.029, and the mass of the 4He atoms produced adds to 8.0052. There is a difference of 0.0238 atomic units, and this missing mass has been converted to energy. Specifically, since an atomic unit equals 931.49 MeV (according to E=mc2), the missing mass has been converted to 0.0238x931.49 or 22.4 MeV.

Answer 4

The energy of fusion comes from the same place the energy of fission does; the loss of binding energy (Strong Atomic Force) that occurs when you fuse two atoms together. In the case of fission, its when you split an atom, but there is still a loss of binding energy that goes into the system, usually as heat.

Answer 5

the nucleus. it is almost too big to stay together and can get to a lower energy state if it fissions into smaller nuclei. the difference in energy is released as heat.

Answer 6

Essentially what happens is that in the nuclear reaction a small proportion of the nuclear mass is annihilated and energy is released as a result, E = mc2