![]() ![]() A single gram of 210Po generates 140 watts of power. A few curies (1 curie equals 37 gigabecquerels) of 210Po emit a blue glow which is caused by excitation of surrounding air. A milligram of 210Po emits about as many alpha particles per second as 4.5 grams of 226Ra. 209Po (half-life 103 years) and 208Po (half-life 2.9 years) can be made through the alpha, proton, or deuteron bombardment of lead or bismuth in a cyclotron.Ģ10Po is an alpha emitter that has a half-life of 138.376 days it decays directly to its daughter isotope 206Pb. 210Po (half-life 138.376 days) is the most widely available. They have atomic masses that range from 194u to 218u. Polonium has 25 known isotopes, all of which are radioactive. Other more neutron rich isotopes can be formed by the irradiation of platinum with carbon nuclei. It has been found that the longer-lived isotopes of polonium can be formed by proton bombardment of bismuth using a cyclotron. Only about 100 grams are produced each year, practically all of it in Russia, making polonium exceedingly rare. Polonium may now be made in milligram amounts in this procedure which uses high neutron fluxes found in nuclear reactors. In 1934 an experiment showed that when natural 209Bi is bombarded with neutrons, 210Bi is created, which then decays to 210Po via β decay. Polonium has been found in tobacco smoke from tobacco leaves grown with phosphate fertilizers, though similar amount occur in everything from cherries to human tissue. The amounts in the Earth's crust are not harmful. It is found in uranium ores at about 100 micrograms per metric ton (1 part in 10 10), which is approximately 0.2% of the abundance of radium. Polonium is a very rare element in nature because of the short half-life of all its isotopes. The Curies first separated out polonium from the pitchblende, and then within a few years, also isolated radium. This spurred the Curies on to find additional radioactive elements. The pitchblende, after removal of the radioactive elements uranium and thorium, was more radioactive than both the uranium and thorium put together. This element was the first one discovered by the Curies while they were investigating the cause of pitchblende radioactivity. Polonium may be the first element named to highlight a political controversy. It was Curie's hope that naming the element after her native land would publicize its lack of independence. Poland at the time was under Russian, Prussian, and Austrian partition, and did not exist as an independent country. Because of its very high toxicity, polonium can be used as a poison (see, for example, Alexander Litvinenko poisoning).Īlso tentatively called "Radium F", polonium was discovered by Marie Skłodowska-Curie and her husband Pierre Curie in 1898 and was later named after Marie Curie's native land of Poland (Latin: Polonia).210Po can be used as an atomic heat source to power radioisotope thermoelectric generators via thermoelectric materials.A non-radioactive alternative is to use a high-voltage DC power supply to ionise air positively or negatively as required. However, beta particle sources are more commonly used and are less dangerous. Devices that eliminate static charges in textile mills and other places.It has been used in this capacity as a neutron trigger or initiator for nuclear weapons. When it is mixed or alloyed with beryllium, polonium can be a neutron source: beryllium releases a neutron upon absorption of an alpha particle that is supplied by 210Po. 3.2 Synthesis by (p, n) and (p,2n) reactions.It is unstable all isotopes of polonium are radioactive. Polonium has been studied for possible use in heating spacecraft. A rare and highly radioactive metalloid, polonium is chemically similar to tellurium and bismuth, and it occurs in uranium ores. Polonium ( pronounced /pəˈloʊniəm/) is a chemical element that has the symbol Po and atomic number 84. ![]()
0 Comments
Leave a Reply. |