Radium, discovery

The historic discovery of radium in 1898 by Marie Curie initiated a remarkable use of this isotope as an early oceanic tracer. Less than 10 years after its discovery,... 

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). 

Marie Curie (Paris) discovery of the elements radium and polonium, the isolation of radium, and the study of the nature and compounds of this remarkable element. 

Although the Curies noted that one equivalent gram of radium released one hundred calorics of heat per hour, they were uninterested in the practical implications of this, as they were both devoted to pure scientific discovery. During their work with pitchblende in 1898, the Curies discovered two new radioactive elements, which they named polonium (in honor of Marie s homeland) and radium. By 1902 they had isolated a pure radium salt and made the first atomic weight determination. 

In 1903, the Curies received the Nobel Prize in physics (with Becquerel) for the discovery of radioactivity. Three years later, Pierre Curie died at the age of 46, the victim of a tragic accident. Fie stepped from behind a carriage in a busy Paris street and was run down by a horse-driven truck. That same year, Marie became the first woman instructor at the Sorbonne. In 1911, she won the Nobel Prize in chemistry for the discovery of radium and polonium, thereby becoming the first person to win two Nobel Prizes. 

In 1921, Irene Curie (1897-1956) began research at the Radium Institute. Five years later she married Frederic Joliot (1900-1958). a brilliant young physicist who was also an assistant at the Institute. In 1931, they began a research program in nuclear chemistry that led to several important discoveries and at least one near miss. The Joliot-Curies were the first to demonstrate induced radioactivity. They also discovered the positron, a particle that scientists had been seeking for many years. They narrowly missed finding another, more fundamental particle, the neutron. That honor went to James Chadwick in England. In 1935,... 

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... 

One curious observation, however, was that pure U actually had a lower radioactivity than natural U compounds. To investigate this. Curie synthesized one of these compounds from pure reagents and found that the synthetic compound had a lower radioactivity than the identical natural example. This led her to believe that there was an impurity in the natural compound which was more radioactive than U (Curie 1898). Since she had already tested all the other elements, this impurity seemed to be a new element. In fact, it turned out to be two new elements—polonium and radium— which the Curies were successfully able to isolate from pitchblende (Curie and Curie 1898 Curie et al. 1898). For radium, the presence of a new element was confirmed by the observation of new spectral lines not attributable to any other element. This caused a considerable stir and the curious new elements, together with their discoverers, achieved rapid public fame. The Curies were duly awarded the 1903 Nobel prize in Physics for studies into radiation phenomena, along with Becquerel for his discovery of spontaneous radioactivity. Marie Curie would, in 1911, also be awarded the Nobel prize in chemistry for her part in the discovery of Ra and Po. 

The guiding principle that was decisive in the choice of Rontgen is also true for Antoine H. Bec-guerel (1852-1908 Nobel Prize for physics 1903 together with Pierre and Marie Curie). His discovery of radioactivity was not only the basis for the unraveling of new elements (radium and polonium by the Curies). Radioactivity and its phenomena became a universal tool that provided succeeding chemists and physicists with insight into the world of atoms. 

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 laboratory notes of Marie and Pierre Curie detailing their discovery of radium still emit such strong radiation that they have to be stored behind lead shields. 

Marie Pierre Curie 1903, physics radioactivity, M.C. 1911, chemistry discovery of radium and polonium)... 

Lind (1961) defines radiation chemistry as the science of the chemical effects brought about by the absorption of ionizing radiation in matter. It can be said that in 1895, along with X-rays, Roentgen also discovered the chemical action of ionizing radiation. He drew attention to the similarity of the chemical effects induced by visible light and X-rays on the silver salt of the photographic plate. This was quickly followed by the discovery of radioactivity of uranium by Becquerel in 1896. In 1898, the Curies discovered two more radioactive elements—polonium and radium. 

These elements have all been named for famous scientists or for the places of their creation. For example, americium, berkelium, and californium were named after obvious geographical locations. Nobelium was named for the Nobel Institute, although later study proved it was not really created there. Curium was named for Marie Curie, the discoverer of radium. Einsteinium was named for the famous physicist, Albert Einstein. Fermium and lawrencium were named for Enrico Fermi and Ernest O. Lawrence, who made important discoveries in the field of radioactivity. Mendelevium was named for the discoverer of the periodic chart. 

Hermetic and Rosicmdan circles such as the Golden Dawn began to engage more publicly with science after the discoveries of radiation, radioactive transformation, and radium. In a case like that of the Alchemical Society, two subjects, alchemy and radiation,4 allowed the groups from sharply different social worlds—those of mainstream science and occultism—to interact. These interactions also contributed to the popular press s alchemical understanding of the newly emerging discourse of atomic physics. 

In the early years of Theosophy during Blavatsky s lifetime, the modem science that most occupied the movement was, without doubt, the theory of evolution rather than Victorian discoveries in physics and chemistry.4 While Blavatksy in Isis Unveiled and Secret Doctrine grappled in a limited way with modem physics and chemistry, she engaged much more fully with the work of alchemists, especially that of Paracelsus. Her defense of alchemical transmutation was based not upon contemporary science—though she asked of transmutation, Is the idea so absurd as to be totally unworthy of consideration in this age of chemical discovery (Isis 1 503)—but rather upon the exalted reputation of medieval and early modem scientists and alchemists who claimed to have witnessed transmutation (1 503-504). Moreover, the major events that launched modem particle physics—the discoveries of X-rays, the electron, radiation, radium, and radioactive decay—all occurred after Blavatsky died in 1891. 

In Soddy s 1908 Interpretation of Radium lectures, he laid out the current state of knowledge about radiation and radium, discussing with scientific specificity (but in relatively accessible terms) the history of the last decade of discoveries in radioactivity and current interpretations of them. But the lectures and book concluded with more imaginative, less strictly scientific speculations about the uses of such knowledge and the powers of the energy released by atomic transmutation. Returning to the subject of alchemy, Soddy noted ... 

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)... 

Marie (NLP 1903, NLC 1911 ) and Pierre (NLP 1903 ) Curie took up further study of Becquerel s discovery. In their studies, they made use of instrumental apparatus, designed by Pierre Curie and his brother, to measure the uranium emanations based on the fact that these emanations turn air into a conductor of electricity. In 1898, they tested an ore named pitchblende from which the element uranium was extracted and found that the electric current produced by the pitchblende in their measuring instrument was much stronger than that produced by pure uranium. They then undertook the herculean task of isolating demonstrable amounts of two new radioactive elements, polonium and radium, from the pitchblende. In their publications, they first introduced the term radio-activity to describe the phenomenon originally discovered by Becquerel. After P. Curie s early death, M. Curie did recognize that radioactive decay (radioactivity) is an atomic property. Further understanding of radioactivity awaited the contributions of E. Rutherford. 

Marguerite Catherine Perey, an assistant to Marie Curie, is credited with the discovery of francium-223 in 1939. Perey discovered the sequence of radioactive decay of radium to actinium and then to several other unknown radioisotopes, one of which she identified as francium-223. Since half of her sample disappeared every 21 minutes, she did not have enough to continue her work, but a new element was discovered. 

---