Radium metal

Radium is the 85th most abundant element found in the Earths crust. Radium is found in the uranium ores pitchblende and chalcolite, which are both very radioactive. Radium metal exists to the extent of only one part to every three million parts of the uranium ore (pitchblende). Only about one gram of radium is found in every seven or eight tons of uranium ore. This scarcity seems to be the reason that only about five pounds of uranium are produced each year in the entire world. Uranium ores are found in the states of Utah, New Mexico, and Colorado in the United States and in Canada, the Czech Republic, Slovakia, Russia, Zaire, and France. 

Feb. 2, 1907 Feb. 20,1907 1907 1907 1909 1910 1910 1911 May 28, 1912 1913 Death of Mendeleev. Death of Moissan. Urbain discovers lutetium. Von Bolton prepares a columbium (niobium) regulus. E. Weintraub prepares pure fused boron. Mme. Curie and M. Debierne isolate radium metal. M. A. Hunter prepares titanium 99.9 per cent pure. Antonoff discovers uranium Y. Death of Boisbaudran. Fajans and Gohring discover uranium X2 (element 91, eka-tantalum). 

RADIUM. [CAS 7440-14-41, Chemical element symbol Ra, at. no. 88, at. wt. 226.025, periodic table group 2 (alkaline earths), mp 700VC, bp 1,140°C, density 5 g/cm3 (20°C). Radium metal is white, rapidly oxidized in air, decomposes H O, and evolves heat continuously at the rate of approximately 0.132 calorie per hour per mg when the decomposition products are retained, and the temperature of radium salts remains about 1,5°C above the surrounding environment. Radium is formed by radioactive transformation of uranium, about 3 million parts of uranium being accompanied in nature by 1 part radium. Radium spontaneously generates radon gas at approximately the rate of 100 mmJ per day per gram of radium, at standard conditions, Radium usually is handled as the chloride or bromide, either as solid or in solution. The radioactivity of the material... 

Radium metal has a bright luster and has many similarities with barium. Tknd yet it is completely different Its radioactivity is strong and dangerous. During Marie Curie s whole adult Hfe, she was exposed to large radiation doses. When she died in 1934, at the age of 67, the cause of death was leukemia. 

Marie Sklodowska Curie, born in Warsaw, Poland, began her doctoral work with Henri Becquerel soon after he discovered the spontaneous radiation emitted by uranium salts.She found this radiation to be an atomic property and coined the word radioactivity for it. In 1903 the Curies and Becquerel were awarded the Nobel Prize in physics for their discovery of radioactivity.Three years later, Pierre Curie was killed in a carriage accident.Marie Curie continued their work on radium and in 1911 was awarded the Nobel Prize in chemistry for the discovery of polonium and radium and the isolation of pure radium metal.This was the first time a scientist had received two Nobel awards. (Since then two others have been so honored.)... 

The Egyptians and Romans used various forms of limestone for building materials and mortars. Earths that were alkalis have been known since the Middle Ages, but it was not until 1808 that Davy isolated calcium, magnesium, barium, and strontium from their oxides or chlorides. Beryllium was found in beryl and emerald by Vauquelin in 1798 and isolated electrolyticaUy by Bussy and Wohler in 1828. Radium chloride was obtained from uranium ores by Marie and Pierre Curie in 1902. Radium metal was prepared electrolyticaUy in 1911. 

Radium metal was first isolated by the electrolysis of the chloride in 1911. Write an equation for this reaction. 

For medical uses, radon-222 formed in the radioactive decay of radium-226 is allowed to collect over the radium metal. Then, the gas is withdrawn and sealed into a glass vial. Following this, the radium is allowed to disintegrate for another period, when a new sample of radon-222 can be withdrawn. The procedure can be continued indefinitely. The process is somewhat complicated by the fact that radon-222 itself undergoes radioactive decay to polonium-218, and so on. The half-lives of radium-226 and radon-222 are 1.60 x 10 years and 3.82 days, respectively. 

The elements in Group II of the Periodic Table (alkaline earth metals) are. in alphabetical order, barium (Ba). beryllium (Be), calcium (Ca). magnesium (Mg), radium (Ra) and strontium (Sr). 

Polonium-210 is a low-melting, fairly volatile metal, 50% of which is vaporized in air in 45 hours at 55C. It is an alpha emitter with a half-life of 138.39 days. A milligram emits as many alpha particles as 5 g of radium. 

L. radius, ray) Radium was discovered in 1898 by Mme. Curie in the pitchblende or uraninite of North Bohemia, where it occurs. There is about 1 g of radium in 7 tons of pitchblende. The element was isolated in 1911 by Mme. Curie and Debierne by the electrolysis of a solution of pure radium chloride, employing a mercury cathode on distillation in an atmosphere of hydrogen this amalgam yielded the pure metal. 

Gr. aktis, aktinos, beam or ray). Discovered by Andre Debierne in 1899 and independently by F. Giesel in 1902. Occurs naturally in association with uranium minerals. Actinium-227, a decay product of uranium-235, is a beta emitter with a 21.6-year half-life. Its principal decay products are thorium-227 (18.5-day half-life), radium-223 (11.4-day half-life), and a number of short-lived products including radon, bismuth, polonium, and lead isotopes. In equilibrium with its decay products, it is a powerful source of alpha rays. Actinium metal has been prepared by the reduction of actinium fluoride with lithium vapor at about 1100 to 1300-degrees G. The chemical behavior of actinium is similar to that of the rare earths, particularly lanthanum. Purified actinium comes into equilibrium with its decay products at the end of 185 days, and then decays according to its 21.6-year half-life. It is about 150 times as active as radium, making it of value in the production of neutrons. 

Barium [7440-39-3] Ba, is a member of Group 2 (IIA) of the periodic table where it Hes between strontium and radium. Along with calcium and strontium, barium is classed as an alkaline earth metal, and is the densest of the three. Barium metal does not occur free in nature however, its compounds occur in small but widely distributed amounts in the earth s cmst, especially in igneous rocks, sandstone, and shale. The principal barium minerals are barytes [13462-86-7] (barium sulfate) and witherite [14941-39-0] (barium carbonate) which is also known as heavy spar. The latter mineral can be readily decomposed via calcination to form barium oxide [1304-28-5] BaO, which is the ore used commercially for the preparation of barium metal. 

The experiment conducted by Rutherford and his co-workers involved bombarding gold foil with alpha particles, which are doubly charged helium atoms. The apparatus used in their experiment is shown in Figure 14-9. The alpha particles are produced by the radioactive decay of radium, and a narrow beam of these particles emerges from a deep hole in a block of lead. The beam of particles is directed at a thin metal foil, approximately 10,000 atoms thick. The alpha particles are delected by the light they produce when they collide with scintilltaion screens, which are zinc sulfide-covered plates much like the front of the picture tube in a television set. The screen... 

Between barium (Group 2, element 56) and lutetium (Group 3, element 71), the 4f orbitals fill with electrons, giving rise to the lanthanides, a set of 14 metals named for lanthanum, the first member of the series. The lanthanides are also called the rare earths, although except for promethium they are not particularly rare. Between radium (Group 2, element 88) and lawrenclum (Group 3, element 103), are the 14 actinides, named for the first member of the set, actinium. The lanthanides and actinides are also known as the inner transition metals. 

Radium, like most other group II metals, is soluble in seawater. Formation of Ra and Ra by decay of Th in marine sediments leads to release of these nuclides from the sediment into the deep ocean. Lead, in contrast, is insoluble. It is found as a carbonate or dichloride species in seawater (Byrne 1981) and adheres to settling particles to be removed to the seafloor. 

The radioactive element is a silvery, shiny, soft metal that is chemically similar to calcium and barium. It is found in tiny amounts in uranium ores. Its radioactivity is a million times stronger that that of uranium. Famous history of discovery (in a shed). Initially used in cancer therapy. Fatal side effects. Small amounts are used in luminous dyes. Radium was of utmost importance for research into the atom. Today its reputation is rather shaky as its decay gives rise to the unpleasant radon (see earlier). In nuclear reactors, tiny amounts of actinium are formed from radium. 

The notion of radium-filled caverns creating precious jewels and metals by transmutation seems to have been a fixture in science fiction stories of the period. The 1929 novella The Radium Pool, first published in Science Wonder Stories by Ed Earl Repp, also features a radium pool that transmutes a cave into precious metals and jewels, acts as a fountain of youth, and provides telepathic and death ray abilities to Jovians who have come to appropriate its radium for Jupiter, the most powerful planet in the universe. 

B—Sodium and radium are metals on the left side of the periodic table. Metals on the left side of the periodic table are very reactive. 

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