particles
These particles got from some radioactive nuclei by speed close to the speed of the light. We know 2 types - electrons and positrons - these have the same mass as electrons, but positive charge ( decay).
Penetration: 1m of air, 1mm of metal e.g.: copper
rays
Invisible electromagnetic waving. They had the highest penetrating power and are ordinary, but not always, emitted from radioactive nucleus after or particle.
Penetration: intensity reduced to 50% by 120m of air or 13mm layer of lead.
Radioactive decay
It is spontaneous splitting of radioactive nucleus. It emits or particles, usually followed by radiation. When nucleus release that particle, it means that nuclear decay occurs, energy is released and another nucleus (and atom) is formed. If it is also radioactive, decaying process continue, until stable (non-radioactive) atom is formed. This series of decays are called decaying queue, decaying chains, radioactive queues or transforming queues.
Half - Life of decay (change) (t1/2)
Time in which half of atoms in sample decays. It is all, what can be exactly predicted, it is impossible to predict decay of whatever simple atom, because atoms are decaying individually and randomly. Each substance have different half-life and its range is wide.
Examples: stroncium-90, 9 minutes;
uranium-238, 4.5x109 years.
Nuclear power plants
Nuclear power plants utilize radioactive materials and the process of nuclear fission to generate the heat and steam needed to run the electrical generators and produce electricity. Because nuclear plants doesn't cause the air pollution, which is associated with the burning of coal or petroleum products, this means that nuclear generating of power is considered as alternative energy source. However, the toxic nature of by-products produced by nuclear fission creates serious problems. And also the method of safely disposing of this radioactive/toxic waste haven't been found. Also volatile fission reaction can lead to a meltdown of the reactor core if the radiation is not properly controlled (e.g.: Chernobyl). Because of these serious problems, the future of nuclear power (nuclear plants ) is uncertain.
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