In a nuclear reaction, energy is released by the combination of two elements into a new element. This process?
540178
I am proud to say that I have witnessed this event on countless occasions as it took place. As lighting falls from the sky, it carries an enormous quantity of energy. It is enough energy to bring together two Oxygen molecules. The ultimate result is a molecule of Ozone. This process is commonly called Nuclear Fusion because the nuclei of the participants come together and a portion of matter is turned into energy in the process.
1130985
Most nuclear weapons rely on fission (the breaking down of a nucleus into smaller nuclei).  This breakdown releases the energy that would otherwise go into holding the nucleus together.  That's not much energy for one nucleus, but breaking a few nuclei releases stray particles that bump into other nuclei and break them  -- which releases more energy, and more stray particles which bump into still more nuclei, and so on.  That's a chain reaction.  This reaction isn't limited to weapons; it also occurs in peaceful uses of nuclear technology such as reactors.  A nuclear weapon simply releases all of the available energy all at once.\n  As to predicting the reaction products, that's largely a function of what fissionable material you start with.  Nuclear physicists (which I am not) know what materials result from the nuclear decay of specific radioactive elements.  How you achieve fission is also a factor; a nucleus will break differently when hit by a fast neutron than it will when hit by a gamma ray.  Fusion is much simpler; if you start with hydrogen, the result is always helium.
480675
no. depending on the exact details its either inverse beta decay or electron capture. both release energy in very small amounts tho, in the form of radiation.
861306
To release the energy contained in fuels, you generally have to apply energy, or "ignite" the fuel. For a log of wood, for example, you would put a fire underneath it of paper or smaller wood. For a gasoline engine, you would use a spark plug and compression to start the release of the fuel's energy. In an atomic (hydrogen) bomb, the Manhattan project detonated many conventional explosives in a sphere around the nuclear fuel to super-compress and heat the Hydrogen, which then blew up.\n\nIn all the above reactions, heat energy contained in the chemical bonds of the fuel was released by the application of "starter" energy either in the form of heat or compression (or both).
952789
fission reaction or fusion? chain reaction? what molecules? neutrons may be? Uranuim isotope? nuclear fuel?\ni can't help you.
297015
It's the joining of two atomic nuclei.
382856
Its nuclear reactions that releases energy in the sun.The hydrogen which is present in the core of the sun is subjected to extreme pressure and temperature due to the billions of tons of gases Present above the core.Under these conditions nuclear fusion reaction takes place and four hydrogen nucleus undergo nuclear fusion to form two helium nucleus. This fusion reaction releases enormous amount of energy which is calculated using the famous equation of Einstein, E=mc*c.(e=energy releases,m=mass lost.c=speed of light).\nThis energy released heats up the gases present in the sun,releasing all sorts of electromagnetic radiations,including light,infra red,Gama rays etc.
642246
In certain Nuclear reactions involving smaller nuclei from hydrogen to Iron, alpha particles will be released. These alpha particles are basically Helium nuclei. When these Helium nuclei are passed through an electron beam, they get converted to pure Helium gas.
908300
A chemical reaction involves only the electrons of the atoms -- the nucleus of each atom remains unchanged.  In addition, the same number of the same types of atoms is present after the reaction as was present before the reaction.\n\nA nuclear reaction involves a change of the nucleus of the atom(s), either splitting one large nucleus into one or more smaller nuclei (fission) or joining multiple nuclei together to form a larger nucleus (fusion).  This means that after a nuclear reaction, there are a different number of different types of atoms than there were before the nuclear reaction.\n\nIn addition, nuclear reaction tends to produce large amounts of high-energy photons (x-rays, gamma rays, etc) and nuclear particles (alpha and beta particles) as a result of the reaction.  Chemical reactions produce low-energy photons (heat and visible light) and do not produce nuclear particles.\n\nIn a nuclear reaction, some of the matter of the original atom is converted into energy -- so the resulting products will have less mass than the total mass of all the original material.  In a chemical reaction, the mass always remains the same because the same number and type of atoms are still present.
988615
atoms splitting apart by fission and protons clinging to the control rods in the reactor. there is steam produced also. and if you REALLY wanna see physical changes, jump in!
64677
Hmm, I don't like that previous answer.  There is a certain amount of energy holding together an atom, say uranium 235.  When bombarded with neutrons, the atom breaks apart into 2 different atoms and releases energy.  No energy is created or destroyed, as it only changes the form.
982438
http://en.wikipedia.org/wiki/Nuclear_fission\n\nEffectively generating energy from breaking down an element to at least two smaller elements.\n\nThis is the reaction that takes place in bombs and power plants. This is distinct from fusion
1012318
More nergy is released in nuclear reaction that chemical reactions because the relatively stable nucleus is disturbed in the nuclear reactions. In chemical reactions only the electrons take part while in nuclear reactions the whole atom including the nuclei take part.
141922
Chemical energy is the amount of heat released from a chemical reaction to do work.  Since not all heat will be utilized, you will have a loss of heat which will lower the efficiency of the process. \n\nIn closer detail to a chemical reaction, studies are made on different reactions to determine the amount of energy released.  One of the best tools to determine this is to look at an Energy vs. time graph.  The barrier to overcome for a chemical reaction to come to completion would be the activation energy (slope to peak); this is the amount needed for a chemical reaction to proceed.  Once the requirements are met, the release of energy (negative slope of the same curve from apex), the difference between starting energy (baseline from beginning before additional energy was applied) and ending energy (the bottom of the slope where m = dE/dt = 0).  If the difference of energy is positive, the reaction is endothermic.  If negative, the reaction is said to be exothermic.  Exothermic reactions are used in many applications to power devices such as steam engines, and gasoline motors which are about 20-30% efficient at most.  Rockets, on the other hand are really inefficient yet they are our main means of propelling stuff into space.\n\nOn the other hand, more subtle means of chemical energy exists in fuel cells and batteries; they power devices through the transfer of electrons and a porous media of some sort connecting the two cells.  Although it is an alternative that to mixing two substances and sparking an explosion.\n\nIf a material spontaneously combusts, it is said that the requirements of meeting the activation energy has been met; look at the reaction of Na(s) with O2(g).  Sodium most readily gives up an electron which the oxygen will take.  Oxygen is more electronegative (It loves electrons more than Sodium).  Oxygen will prefer to take electrons from Sodium as opposed from it's own because Sodium would feel more satisfied with having one less electron.  Oxygen - Oxygen bonding on the other hand would mean that oxygen would have to share 4 electrons to feel satisfied (remember, octet rule - higher stability with complete s, p, d, orbitals filled).  So what does this mean?\n\nChemical energy is due to the release of energy due to trying to BEST satisfy the conditions of the electron-nucleus relationship.  If the nucleus requires 10 electrons, they are going to be nearby but in a highly defined probable region where they will linger to make the nucleus feel happy.  If another buddy (compound) comes along and offers the POTENTIAL for a better and more STABLE life, the substance will jump on it, thus reducing the potential energy of the whole substance.\n\nAlthough, look at this you would think chemical energy would even come from nuclear power plants.  But, don't let it fool you.  Nuclear power is a different beast itself.  It does not arise from chemical reactions but from decay of nucleus to produce energy.
324432
Quick summery:\n\nFusion produces energy by taking very light elements, like hydorgen, and combining them together to form heavier ones like helium.  4H -> 1He.  If you take a look at the mass of 4 hydrogen atoms you will find that they have more mass than 1 helium atom.  This extra mass is converted into energy in fusion (E = mc^2).\n\nNow this produces a ton of energy (it is what powers the sun), but you need extream conditions (high temperature and pressure) to do it.  In order to make a hydrogen bomb, that is a bomb that uses fusion to generate the energy to do its dirty work, we need a source of intense heat.\n\nThat is why typically we trigger our hydrogen bombs with a small atomic bomb.  An atomic bomb generates energy through breaking large elements (uranium) into lighter ones.  Just like fusion, there is a mass difference between what you start with, and what you end with.  That missing mass goes into eneregy.  Fission is easy to strat, just get enough fissionable material together and presto.\n\nSo, you use the energy/heat produced by the little atomic bomb to super-heat your fusion fuel (hydrogen isotopes), and bang -> hydrogen bomb.\n\nTo be specific it is actually a three-stage detonation.  You use a conventional bomb to set off the fission (atomic) bomb, which in turn sets off the fusion (hydrogen) bomb.
51091
During a chemical reaction, existing bonds are broken, atoms are rearranged and new bonds are formed.
330129
The doesn't really "burn" in the sense of chemically combining hydrogen and oxygen.  It shines because of energy produced by nuclear fusion.\n\nIn physics, nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of energy depending on the masses of the nuclei involved. Iron and nickel nuclei have the largest binding energies per nucleon of all nuclei and therefore are the most stable. The fusion of two nuclei lighter than iron or nickel generally releases energy while the fusion of nuclei heavier than them absorbs energy; vice-versa for the reverse process, nuclear fission.\n\nNuclear fusion of light elements releases the energy that causes stars to shine and hydrogen bombs to explode. Nuclear fusion of heavy elements (absorbing energy) occurs in the extremely high-energy conditions of supernova explosions. Nuclear fusion in stars and supernovae is the primary process by which new natural elements are created. It is this reaction that is harnessed in fusion power.\n\nIt takes considerable energy to force nuclei to fuse, even those of the least massive element, hydrogen. But the fusion of lighter nuclei, which creates a heavier nucleus and a free neutron, will generally release more energy than it took to force them together — an exothermic process that can produce self-sustaining reactions.\n\nThe energy released in most nuclear reactions is much larger than that for chemical reactions, because the binding energy that holds a nucleus together is far greater than the energy that holds electrons to a nucleus. For example, the ionization energy gained by adding an electron to a hydrogen nucleus is 13.6 electron volts -- less than one-millionth of the 17 MeV released in the D-T (deuterium-tritium) reaction shown to the top right.\n\nThe steps of the main cycle of nuclear fusion in stars were worked out by Hans Bethe.  He won the Nobel prize for this work.