Polonium

Polonium. A highly radioactive chemical element that is a member of the chalcogen family. Its atomic symbol is Po , atomic number 84 and its use is very dangerous. The damage occurs by absorption of the energy of alpha particles in the tissue. The maximum allowable body quantity is 0.03 microcuries. Polonium is a volatile metal , reducible to 50% after 45 hours in air at a temperature of 328 Kelvin (55ºC).

Summary

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  • 1 Features
    • 1 General
    • 2 Obtaining
  • 2 History
    • 1 Applications
  • 3 Effects on humans
  • 4 Curiosities
  • 5 Sources

characteristics

General

It is a very rare natural element: it represents 2×10-14% by weight of the bark; Uranium ores contain about 100 micrograms of the element per ton. Its abundance is only 0.2% that of radium . In 1934 natural bismuth (209-Bi) was bombarded with neutrons and 210-Bi, father of polonium, was obtained; milligrams can now be prepared by this method, using the large neutron fluxes of nuclear reactors.

Chemically it resembles tellurium and bismuth . It dissolves in dilute acids and with H2S precipitates polonium sulfide (PoS), black. It is slightly soluble in alkalis. Was prepared from polonium metal hydroxide and other compounds in the presence of ammonia concentrated aqueous or anhydrous liquid ammonia.

It is extremely toxic and highly radioactive. Polonium has been found in uranium ores and in tobacco smoke and as a pollutant. All elements from polonium are significantly radioactive, this naturally occurring chemical element, but it was in 1898 that Pierre and Marie Curie first extracted it from pitchblende or uranite. There are 27 isotopes of polonium, with an atomic mass number from 192 to 218. Polonium 210 is the only one that is available in nature and is very difficult to handle. It is currently used in nuclear power plants and atomic research centers. In very small quantities, it is also present in cigarettes and is used in some photography techniques

Obtaining

Although it is an element of natural origin, it is an element that is only present in natural uranium minerals at a rate of 100 micrograms per ton, therefore it is obtained by bombarding natural bismuth (209Bi) with neutrons, the isotope of bismuth is obtained 210Bi, which by disintegration gives rise to polonium.

Polonium can be created in milligram quantities by this procedure, using large neutron fluxes, such as those found in nuclear reactors. It usually appears in the form of rust . It is a red powder that humans do not perceive and that is only observable in industrial environments, for example when it is handled in nuclear power plants.

History

Applications

  • It is used in brushes to remove dust from photographic film.
  • In heat sources for space probes.
  • Mixed or alloyed with beryllium it is a source of neutrons.
  • Alpha ray source with little gamma radiation. Heat source of thermoelectric batteries (nuclear batteries) in satellites.
  • Nuclear power plants are where the highest concentrations can be found. It is necessary to handle it with lead gloves and in special environments.

Effects on humans

 

Negative effects

Ingesting or inhaling an excessive amount can have the same consequences as the Hiroshima radiation , but individually. These effects can be noticed from the third day, they are not immediate.
The first symptoms are hair loss and gastrointestinal complaints. Then the liver and kidneys fail; metabolism and bone marrow are paralyzed.
Death will be due to multi-organ failure. If exposure is reduced, only gastrointestinal symptoms may appear.

Curiosities

 

Cigar, contains polonium

  • 210-Po is so dangerous that handling microgram quantities requires special equipment and used under strict safety procedures.
  • Cigarette or tobacco smoke contains a large amount of carcinogenic substances such as benzene, polonium, lead, carbon monoxide , and other substances that are mixed in tar (a mixture of gases that results from the combustion of tobacco cuttings With paper); This is the fundamental reason why smoking is considered a very harmful habit for health , not only that of the active smoker but also, and more dangerously, passive smokers.
  • From half a milligram it can be fatal by radiation. It is 50 times more radioactive than uranium.
  • The maximum allowed concentration of soluble polonium compounds in air is 2 x 10-11 microcuries / cm3.
  • Polonium 210 produces a slow and suffering death.

 

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