different between nuclear fission and nuclear fusion
Answers
Nuclear Fission
Nuclear fission is the process by which a very heavy, unstable nuclei decays into two or more smaller nuclei
An unstable form of Uranium, Uranium-235, decays when it exceeds critical mass. A single neutron added to the nucleus causes it to break into two parts, resulting in two smaller nuclei, more neutrons and of course one, two or all three forms of radiation (Alpha, Beta and Gamma). The expelled neutrons then go into the nuclei of adjacent U-235 atoms, causing them to split in two. This is chain reaction releases huge amounts of energy, as the masses of the products is slightly less than that of the reactants.
Although the mass may seem insignificantly small, Einstein’s equation shows E=MC(^2)
Meaning that a very small mass is equal to a lot of energy
Fission is mainly used to power nuclear power plants and was used in the primary atomic bombs.
Nuclear Fusion
Nuclear fusion on the other hand is a completely different story. Nuclear fusion is the joining of two light nuclei, to form a single heavy nuclei. This may sound easy, but remember that nuclei contain protons, protons are positively charged and they would never come close to each other. To do this you need extremely high temperatures and pressure ( like that in the core of our Sun ). Hydrogen isotopes fuse together to form helium. Sun fuses 620 million metric tons of hydrogen each second. The products are neutrinos, positrons and gamma rays. Photons and heat are also generated
Nuclear fusion, as mentioned before, requires extreme conditions in order to overcome the repulsion between the protons. Such conditions cannot be mimicked at safe scales on Earth.
Fusion is used in hydrogen bombs, where the extreme temperatures are initially reached by detonating a primary fission device.
Answer:
Nuclear Fusion :
1) The reaction is possible only at a very high temperature (≈ K) and a very high pressure.
2) Fusion reaction cannot be controlled.
Nuclear Fission :
1) This reaction is possible at ordinary temperature and ordinary pressure.
2) Fission process can be controlled.