Does nuclear fusion break the law of conservation of energy?

Question

The law states that energy cannot be created or destroyed, but aren't you creating energy if you get back more energy than you put into it? Just a thought

Answer 1

If you consider mass as a form of energy, which you should according to Einstein's E=mc2 equation, then the law isn't broken.

With a nucleus some of the mass of the proton/neutrons is converted into energy. This energy is required to hold the protons and neutrons together. For example the mass of 2 individual protons and 2 individual neutrons is greater than the mass of a helium nucleus (2 protons and 2 neutrons).

When you fuse two light elements some of this energy is given off.

Answer 2

Absolutely not, although it might seem that way at first glance.

Fusion marvellously demonstrates that Einstein's famous E=mc^2 is correct; there is an equivalence between matter and energy. Adding energy to particles--that is, increasing their velocity and thus temperature--makes them more massive. Conversely, certain subatomic reactions (such as the mutual annihilation of an electron and antielectron [aka a positron]) can release tremendous amounts of energy by eliminating an equivalent amount of matter.

In the standard fusion reaction exploited in H-bombs and fusion reactors, two different isotopes of hydrogen--one containing one neutron and one proton, the other containing two neutrons and one proton--are slammed into each other at sufficient energy to produce a helium nucleus containing two neutrons and two protons. The leftover neutron is emitted. From this simple explanation, mass would seem to be conserved (3N, 2P in; 3N, 2P out). But in fact the mass of the newly created He nucleus is less than the sum of the masses of neutrons and protons that went into it. The missing mass has been converted to energy; that energy is carried by the fast neutron emitted in the reaction.

Thus neither mass nor energy, if they are considered strictly separately, are conserved in a fusion reaction. But the sum of mass and energy--which in relativistic physics is called rest-mass and is what the law of conservation of energy applies to--is absolutely conserved.

Answer 3

I would not like to call the answerers above liars, but the Law of Conservation of Energy has been revised. Forgive me, because I don't remember who revised it, but it states, "In non-nuclear events, the energy can be neither created nor destroyed." Therefore, you may, or may not break the Law of Conservation of Energy during nuclear fusion.

Answer 4

The law of conservation of mass and law of conservation of energy have been combined into the law of conservation of mass and energy, to explain the release of energy in nuclear fission and fusion. A small amount of mass m is converted into a large amount of energy E by the famous equation developed by Einstein, E = m.c^2 where c is the velocity of light in vacuum. Thus in nuclear fission and fusion, a large amount of energy is released.

So, no law of conservation is broken.

Answer 5

No, not at all. Fusion takes lighter atoms and fuses them into heavier atoms, but if you weigh all of the products afterwards their mass would be very slightly less than the original starting materials. Big atoms use fission to break apart and release energy. What you need to study is binding energy and (if I remember right) the binding energy curve of the periodic chart of elements. Try reading,
Wikipedia Binding Energy
http://en.wikipedia.org/wiki/Binding_Energy

Answer 6

No it doesn't. Mass is really just binded energy. Fusion up to Iron gives off energy, while after iron, fission gves off energy.
Iron has the most stable nucleus of all the elements, for reasons that are still highly mysterious.

Answer 7

the law of conserv of energy cannot be broken.
i think ,during nuclear fusion mass turns into energy but i am not so sure about it