We transform the energy locked up in nature in a more easy form that can be used in our homes and factories. This defines when we say that energy can never be created or destroyed but can only be transformed from one form to another.
The earth receives energy from the sun in the form of heat and light. Part of this energy is stored as chemical energy in our food and in fuels such as wood, coal and oil. On a very small scale, the conversion of mass into kinetic energy can be seen in radioactivity when the nucleus of an atom of one element transforms into another and emits radiation including gamma rays (high energy X-rays) and high speed beta particles (electrons).
The mass of the new atom is less than that of the old atom by an amount equivalent to the energy released, as predicted by the famous equation E=mc2. There is however no known way of changing the rate at which radioactive materials decay and although radioactive materials can be made artificially, the energy needed to do this much more that the energy releases on decay.
How Nuclear Energy Works?
Electricity through nuclear energy is produced in the same way as it we do it by burning coal, oil or natural gas. When burnt, the heat formed produces steam. The steam then turns turbines. The turbines turns generators which produce electricity. The difference between the plants that use coal and the plants that use uranium as fuel is that here we don’t burn anything. In fact, here bundles of radioactive element uranium rods are placed into the reactor.
The uranium rods are nothing but small vertical ceramic pellets that are packaged into long, vertical tubes. Nuclear fission process takes place inside the reactor causing individual atoms to split by shooting neutrons at them. The uranium nuclei split and release energy in the form of heat. The released neutrons then split further uranium nuclei.
Proton and neutron are the major two particles that comprise the mass of the nucleus of an atom. The protons are positively charged while the neutron is without any charge, that is neutral. The nuclear energy is produced from something called chain reaction. The most important thing in occurring chain reaction is the presence of the heaviest element called uranium-235. The nuclei of uranium can split into two by bombarding. This results in formation of two lighter elements along with the production of a lot of protons. These protons consequently caused more reaction. Only one isotope of uranium seemed to be fissionable, uranium-235. Its nucleus contains 92 protons and 143 neutrons. When they acquire an extra neutron the nuclei of most elements return to a stable state by changing a neutron into a proton and releasing an electron in the process.
However, when a uranium nucleus splits, the new nuclei formed have far too many neutrons to support a few (usually two or three) are ejected unchanged. The two nuclei are still overloaded and decay at different rates by giving off radioactivity. In doing so, they may change into other elements several times. As the uranium nucleus does not split evenly down the middle, and not always in the same way, the number of different stable and radioactive elements left is very large. They are called fission products.
Only one part in 140 of natural uranium consists of the isotope uranium -235. The rest is uranium-238 whose nucleus contains 92 protons and 146 neutrons. This isotope absorbs neutron s strongly, turning first into neptunium-239 and then into plotunium-239, an element which is not found in nature but fissionable. Fission of one nucleus is unlikely to cause fission because the neutrons produced will be absorbed by elements other than uranium-235. Even when pure uranium has been separated out, the absorption of neutrons by the uranium -238 prevents any chain reaction from developing; unless the neutrons can be slowed down to give them a better chance of causing fission in the uranium-235.
Nuclear energy is generated from the power reactors. In the reaction of uranium-235, the amount of energy released is far more than the energy released during the burning of coal or petroleum. The uranium is usually referred to as the fuel and assemblies of fuel built to produce nuclear heat are called power reactors. The heat generated in the fuel is transferred to a liquid or gas. This carries the heat to a place where it can be used, for example, to make steam to drive turbines to produce electricity. Spare neutrons are not needed to continue the chain reaction.
Another way to harness nuclear energy is to join two light weight nuclei and the process is called fusion. However, the energy produced is one-tenth of that of fission.
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