Properties of Radium

Langmuir D, Melchoir D (1985) The geochemistry of Ca, Sr, Ba, and Ra sulfates in some deep brines from the Palo Duro Basin, Texas. Geochim Cosmochim Acta 49 2423-2432 Langmuir D, Reise AC (1985) The thermodynamic properties of radium. Geochim Cosmochim Acta 49 1593-1601... 

For instance, Besant commented on Sir William Ramsay s November 26, 1903 lecture to the London Institution on the properties of radium, where he argued that it seemed that the dreams of the alchemists were not such folly as the wiseacres had thought, even though their methods did amount, as someone has said, to little more than a sort of cookery. It might happen that in time the changing of tin... 

Less than a year after her husband s death, Mme. Curie accepted a professorship at the University of Paris. With the able assistance of Professor Andre Debierne, who took charge of the laboratory and taught for many years an ever-increasing number of students from all parts of the world, she directed the instruction and research in radioactivity (86). When the university acquired new land, it laid out a street called the Rue Pierre Curie and built a laboratory for her. The Curie Institute and the Pasteur Institute work in close harmony, and Mme. Curie spent much of her time on researches dealing with the therapeutic properties of radium and radon (69). During World War I she had complete charge of the radiological service in French military hospitals. 

Table 3-2 lists important physical properties of radium and selected radium compounds. Radioactive properties of the four naturally-occurring radium isotopes are listed in Table 3-3. In addition to the naturally occurring isotopes, there are 12 other known isotopes of radium. The principal decay schemes of the uranium and thorium decay series that produce the naturally-occurring radium isotopes are presented in Figure 3-1.

Physical and Chemical Properties. Although some of the physical and chemical properties of radium and radium compounds have not been determined, many of those that are needed to evaluate its behavior in the environment are known. The adsorption-desorption behavior of radium with geologic materials depends on the specific system under study and should be determined on a case-by-case basis. Also, thermodynamic and kinetic data for solid solution formation are scarce. Research in this area would facilitate modeling the fate of radium in water. 

Langmuir D, Riese AC. 1985. The thermodynamic properties of radium. Geochimica et Cosmochimica Acta 49 1593-1601. 

After helium and argon had been discovered the existence of neon, krypton, xenon, and radon was clearly indicated by the periodic law, and the search for these elements in air led to the discovery of the first three of them radon was then discovered during the investigation of the properties of radium and other radioactive substances. While studying the relation between atomic structure and the periodic law Niels Bohr pointed out that element 72 would be expected to be similar in its properties to zirconium. G. von Hevesy and D. Coster were led by this observation to examine ores of zirconium and to discover the missing element which they named hafnium. 

Radium. Compounds of radium are closely similar to those of barium. The only important property of radium and its compounds is its i v idioactivity, which is discussed in Chapter 33. 

The radioactive properties of radium are the greatest concern and overwhelm all else. All radioactive materials may cause harm when decay particles are released that disrupt many critical cell functions, including DNA replication. Radioactive materials may also produce toxicity not related to their radioactive behavior. Like barium compounds, radium... 

The elements Ca, Sr, Ba and Ra are collectively known as the alkaline earth metals. We shall have little to say about radium it is radioactive and is formed as (a-emitter, h = 1622yr) in the decay series. Uses of radium-226 in cancer treatment have generally been superseded by other radioisotopes. The properties of radium and its compounds can be inferred by extrapolation from those of corresponding Ca, Sr and Ba compounds. 

This chapter has focused on the properties of elements that exhibit radioactivity. Because radioactivity can have harmful effects on human health, very stringent experimental procedures and precautions are required when imdertaking experiments on radioactive materials. As such, we typically do not have experiments involving radioactive substances in general chemistry laboratories. We can nevertheless ponder the design of some hypothetical experiments that would allow us to explore some of the properties of radium, which was discovered by Marie and Pierre Curie in 1898. 

In 1898, Marie Sklodowska Curie (1867-1934) and her husband Pierre Curie (1859-1906) turned their research interests to radioactivity. In a short time, the Curies discovered two new elements, polonium and radium, both of which are radioactive. To confirm their work on radium, they processed 1 ton of pitchblende residue ore to obtain 0.1 g of pure radium chloride, which they used to make further studies on the properties of radium and to determine its atomic mass. 

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). 

Indeed, the Theosophical infusion of matter with life, and the ability of life force and will to effect the changes in matter demanded by spiritual alchemy and occult chemistry, seemed to find some support from the newly discovered phenomenon of radiation. Besant s On the Watch-Tower column, for instance, noted with excitement an article on the origin of life by Butler Burke published in the Daily Chronicle in 1905. There, Burke noted that radium may be that state of matter that separates, or perhaps unites, the organic and the inorganic worlds, and that radioactivity endows matter with some of the properties of organic matter (quoted in [Besant] 1905a, 481). 

Recent discoveries would appear to suggest that this mysterious Fire of Life, which, whatever else it may have been, was evidently a force and no true fire, since it did not burn, owed its origin to the emanations from radium, or some kindred substance. Although in the year 1885, Mr. Holly would have known nothing of the properties of these marvelous rays or emanations, doubtless Ayesha was familiar with them and their enormous possibilities, of which our chemists and scientific men have, at present, but explored the fringe. (1905, 167)... 

Radium salts have the property of causing surrounding objects to become temporally radioactive. This "induced radioactivity," as it may be called, is found to be due to the... 

While studying radium, Friedrich Ernst Dorn (1848—1916) found that it gave off a radioactive gas that, when studied in more detail, proved to be the sixth noble gas. Dorn was given credit for its discovery in 1900. He called it radon, a variation of the word radium. Sir Wdham Ramsay and R. W. Whytlaw-Gray, who also investigated the properties of radon, called it niton from the Latin word nitens, which means shining. Several other scientists who worked with radon named it thoron because of the transmutation of radon-220 from the decay of thorium. However, since 1923, the gas has been known as radon because it is the radioactive decay gas of the element radium. The name is derived from the Latin word radius, which means ray. ... 

Marie Curie discovered radium in her laboratory in Paris in 1898. The unique properties of this naturally occurring radioactive element suggested to many that it had therapeutic uses. In the early 1900s, radium therapy was accepted by the American Medical Association. Radium was thought to cure a range of illnesses including... 

At the time of the discovery of radio-activity, about seventy-five substances were called elements in other words, about seventy-five different substances were known to chemists, none of which had been separated into unlike parts, none of which had been made by the coalescence of unlike substances. Compounds of only two of these substances, uranium and thorium, are radio-active. Radio-activity is a very remarkable phenomenon. So far as we know at present, radio-activity is not a property of the substances which form almost the whole of the rocks, the waters, and the atmosphere of the earth it is not a property of the materials which constitute living organisms. It is a property of some thirty substances—of course, the number may be increased—a few of which are found widely distributed in rocks and waters, but none of which is found anywhere except in extraordinarily minute quantity. Radium is the most abundant of these substances but only a very few grains of radium chloride can be obtained from a couple of tons of pitchblende. 

Dorn as a product of the radioactive decay of radium. Ramsay made enough of it to measure its properties in 1908. 

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