What is a nuclear fusion and where does it usually take place?

Answer 1

A2. There are two different processes with similar-sounding names, Fusion and Fission.

Nuclear fusion is the process where several atoms are combined to make a new element. For example, in our Sun, four hydrogen atoms are fused to make two Deuterium atoms, and these are then fused to make one helium atom. This process releases much energy - the heat of our Sun.

Another useful fusion product is carbon, produced under conditions of >100 million Kelvin, and when three Helium nuclei are forced together long enough to make one atom of carbon. This process needs the energy inside a giant star or a supernova for success. This carbon is then scattered in a stellar explosion and ultimately coalesces with other material to form a planet such as ours. Thus our Solar system is a third-generation system.

Nuclear fission is the process of breaking apart the structure of an atom and thus releasing the binding energy of the atom, and also the energy contained in a neutron (Which has a half-life of a few minutes). Nuclear power stations and the various atomic bombs are examples of this process.