Radon radioactivity

The characteristic feature of the uranium exploration industry is the radioactivity of all wastes. The quality of these wastes, such as radon, radioactive aerosols, and dust emitted to the atmosphere, depends on mine production and the radioactive budget in the mines. For example, middle range mine exploring the ores with n x 10 1-10 2% of U content emits to the atmosphere up to 8 x 1010 Bq/day of radon. 

Radon can be isolated from radium by several methods. An aqueous solution of radium salt such as radium bromide is heated, liberating radon. Radioactive bombardment then decomposes water to oxygen and hydrogen. Radon is separated from the gaseous mixture by condensation in tiny tubes placed in liquid air. The tubes then are sealed by melting. A gold or platinum coating is applied to form the radon seeds used in radiation therapy. 

General mention should be made of the a-emitters radium 226, polonium 210, radon (radioactive inert gas) 220 and 222, uranium isotopes and thorium isotopes. 

Radon, sealed in small capsules called seeds , has been used as a radioactive substance in medicine, but is being superseded by more convenient artificially-produced radioisotopes. 

Care must be taken in handling radon, as with other radioactive materials. The main hazard is from inhalation of the element and its solid daughters which are collected on dust in the air. Good ventilation should be provided where radium, thorium, or actinium is stored to prevent build-up of the element. Radon build-up is a health consideration in uranium mines. Recently radon build-up in homes has been a concern. Many deaths from lung cancer are caused by radon exposure. In the U.S. it is recommended that remedial action be taken if the air in homes exceeds 4 pCi/1. 

Radon-222 [14859-67-7] Rn, is a naturally occuriing, iaert, radioactive gas formed from the decay of radium-226 [13982-63-3] Ra. Because Ra is a ubiquitous, water-soluble component of the earth s cmst, its daughter product, Rn, is found everywhere. A major health concern is radon s radioactive decay products. Radon has a half-life of 4 days, decayiag to polonium-218 [15422-74-9] Po, with the emission of an a particle. It is Po, an a-emitter having a half-life of 3 min, and polonium-214 [15735-67-8] Po, an a-emitter having a half-life of 1.6 x lO " s, that are of most concern. Polonium-218 decays to lead-214 [15067-28A] a p-emitter haviag = 27 min, which decays to bismuth-214 [14733-03-0], a p-emitter haviag... 

Argon-40 [7440-37-1] is created by the decay of potassium-40. The various isotopes of radon, all having short half-Hves, are formed by the radioactive decay of radium, actinium, and thorium. Krypton and xenon are products of uranium and plutonium fission, and appreciable quantities of both are evolved during the reprocessing of spent fuel elements from nuclear reactors (qv) (see Radioactive tracers). 

Radon is the heaviest of the hehum-group elements and the heaviest of the normal gaseous elements. It is strongly radioactive. The most common isotope, Rn, has a half-life of 3.825 days (49). Radon s scarcity and radioactivity have severely limited the examination of its physical properties, and the values given ki Table 3 are much more uncertain than are the values Hsted for the other elements. 

Loss of radon in the ocean occurs typically through radioactive decay (producing four short-lived daughters before decaying to °Pb) or loss to the atmosphere at the air-sea interface. Loss of radon owing to turbulence or diffusion at the air-sea interface leads to a depletion of radon with respect to "Ra, allowing for studies on gas exchange at this interface. ... 

Radon gas is formed in the process of radioactive decay of uranium. The distribution of naturally occurring radon follows the distribution of uranium in geological formations. Elevated levels have been observed in certain granite-type minerals. Residences built in these areas have the potential for elevated indoor concentrations of radon from radon gas entering through cracks and crevices and from outgassing from well water. 

Radon (Rn) and Radon Decay Products Radon is a radioactive gas formed in the decay of uranium. The radon decay products (also called radon daughters or progeny) can be breathed into the lung where they continue to release radiation as they further decay. 

Radon A radioactive element, the heaviest of the noble gases, formed by the radioactive decay of radium. 

Radon daughters The series of unstable isotopes that are formed as radon atoms undergo radioactive decay. 

The isolation and identification of 4 radioactive elements in minute amounts took place at the turn of the century, and in each case the insight provided by the periodic classification into the predicted chemical properties of these elements proved invaluable. Marie Curie identified polonium in 1898 and, later in the same year working with Pierre Curie, isolated radium. Actinium followed in 1899 (A. Debierne) and the heaviest noble gas, radon, in 1900 (F. E. Dorn). Details will be found in later chapters which also recount the discoveries made in the present century of protactinium (O. Hahn and Lise Meitner, 1917), hafnium (D. Coster and G. von Hevesey, 1923), rhenium (W. Noddack, Ida Tacke and O. Berg, 1925), technetium (C. Perrier and E. Segre, 1937), francium (Marguerite Percy, 1939) and promethium (J. A. Marinsky, L. E. Glendenin and C. D. Coryell, 1945). 

Element 86, the final member of the group, is a short-lived, radioactive element, formerly known as radium-emanation or niton or, depending on which radioactive series it originates in (i.e. which isotope) as radon, thoron, or actinon. It was first isolated and studied in 1902 by E. Rutherford and F. Soddy and is now universally known as radon (from radium and the termination-on adopted for the noble gases Latin radius, ray). 

The price per m of the other noble gases is considerably higher (Ne 70, Kr 350 and Xe 3500, and this tends to restrict their usage to specialist applications only. Radon has been used in the treatment of cancer and as a radioactive source in testing metal castings but, because of its short half-life (3.824 days) it has been superseded by more convenient materials. Such small quantities as are required are obtained as a decay product of Ra (1 g of which yields 0.64 cm in 30 days). 

Radon (Rn) is a naturally occurring radioactive gas. Radon enters buildings from underlying soil and rocks as soil gas is drawn into buildings. 

Although the nucleus of the uranium atom is relatively stable, it is radioactive, and will remain that way for many years. The half-life of U-238 is over 4.5 billion years the half-life of U-235 is over 700 million years. (Half-life refers to the amount of time it takes for one half of the radioactive material to undergo radioactive decay, turning into a more stable atom.) Because of uranium radiation, and to a lesser extent other radioactive elements such as radium and radon, uranium mineral deposits emit a finite quantity of radiation that require precautions to protect workers at the mining site. Gamma radiation is the... 

Radon is a radioactive gas that can cause hmg cancer. It has been detected in the basements of some homes. How many protons are there in a Rn-220 atom How many neutrons ... 

The chemistry of xenon is much more extensive than that of any other noble gas. Only one binary compound of krypton. KrF2, has been prepared. It is a colorless solid that decomposes at room temperature. The chemistry of radon is difficult to study because all its isotopes are radioactive. Indeed, the radiation given off is so intense that it decomposes any reagent added to radon in an attempt to bring about a reaction. 

Rn. a radioactive isotope of radon, is a decay product of naturally occurring uranium-238. Because it is gaseous and chemically... 

Radioactivity The ability possessed by some natural and synthetic isotopes to undergo nuclear transformation to other isotopes, 513 applications, 516-518 biological effects, 528-529 bombardment reactions, 514-516 diagnostic uses, 516t discovery of, 517 modes of decay, 513-514 nuclear stability and, 29-30 rate of decay, 518-520,531q Radium, 521-522 Radon, 528 Ramsay, William, 190 Random polymer 613-614 Randomness factor, 452-453 Raoult s law A relation between the vapor pressure (P) of a component of a solution and that of the pure component (P°) at the same temperature P — XP°, where X is the mole fraction, 268... 

The radioactive gas radon seeps out of the ground a product of radio. tiv< processes deep in the Earth. There is now some concern that its. iimnlation in buildings and its nuclear decay products can lead to dangerou, . h Vs I-, ot... 

C02-0017. Recently, there has been concern about pollution in the home from radon, a radioactive gas whose elemental molar mass is 222 g/mol. The Environmental Protection Agency believes that a level of radon of 3.6 X 10" g / i of air is unhealthy. At this level, how many moles of radon would there be in a living room whose volume is 2455 L How many atoms is this ... 

Radon-222 is an unstable nuclide that has been detected in the air of some homes. Its presence is a concern because of high health hazards associated with exposure to its radioactivity. Gaseous radon easily enters the lungs, and once it decays, the products are solids that remain embedded in lung tissue. Radon-222 transmutes to a stable nuclide by emitting a and P particles. The first four steps are a, a, P, p. Write this sequence of nuclear reactions and identify each product. 

Total exposures vary considerably with human activities as well. Frequent flyers, for example, receive higher doses of radiation because the intensity of cosmic radiation is significantly greater at high altitude than it is at ground level. Residents in locations such as Montana and Idaho, where there are uranium deposits, receive higher doses of radiation from radon, one of the radioactive decay products of uranium. 

The first person to identify the hydrogen ion as a component of all atoms was Ernest Rutherford. Rutherford had his hand in virtually every aspect of atomic research. By 1919, he had discovered alpha and beta rays, found a new element (radon), won a Nobel Prize for his work with radioactive elements, and demonstrated that atoms had nuclei. For good measure, in 1914, he was knighted. However, still more discoveries and honors awaited him. 

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