Perey, Marguerite

Francium was first identified in 1939 by the elegant radiochemical work of Marguerite Perey who named the element in honour of her native country. It occurs in minute traces in nature as a result of the rare (1.38%) branching decay of Ac in the series ... 

Francium (Fr, [Rn] . 1), name and symbol, after France, the country where it was prepared (Curie Institute in Paris). Discovered (1939) by Marguerite Perey. Very rare in nature, artificially prepared, highly radioactive. 

ORIGIN OF NAME In 1939 Marguerite Perey (1909-1975), a French physicist who worked for the Curie institute in Paris, named the newly discovered element after her country—France. 

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. 

Francium Fr 1939 (Paris, France) Marguerite Perey (French) 62... 

French chemist Marguerite Perey Heavy, unstable, alkali metal produced by radioactive decay of uranium and thorium probably less than one ounce is present in the Earth s crust. 

French physicist Marguerite Perey in 1939 and named after France, weighahle amount ever has been prepared. 

The actual discovery was made by Mile. Marguerite Perey at the Curie Institute in Paris. In 1939 she purified an actinium preparation by removing all the known decay products of this element. In her preparation she observed a rapid rise in beta activity which could not be due to any known substance. She was able to show that, while most of the actinium formed radioactinium, an isotope of thorium, by beta emission, 1.2 0.1 per cent of the disintegration of actinium occurred by alpha emission and gave rise to a new element, which she provisionally called actinium K, symbol AcK (35, 36). This decayed rapidly by beta emission to produce AcX, an isotope of radium, which was also formed by alpha emission from radioactinium. Thus AcK, with its short half-life, had been missed previously because its disintegration gave the same product as that from the more plentiful radioactinium. 

Mile. Marguerite Perey detects element 87 (francium) which is formed by the alpha-disintegration of a small percentage of the atoms of actinium. 

The element francium is named for the country of France and its most stable isotope is known as actinium K. Dimitri Mendeleev assigned it the name eka-cesium prior to its actual discovery, although at this time it was also known as russium, virginium, and moldavium. Marguerite Perey, a one-time assistant of Marie Curie, discovered francium in 1939. It is not found in its elemental state and less than one ounce is thought to exist in Earth s crust at any one time. 

Francium may be the rarest element found on Earth s surface. Some experts believe that no more than 15 grams (less than an ounce) of the element exist in Earth s crust. The element was discovered in 1939 by French chemist Marguerite Perey (1909—1975). All isotopes of francium are radioactive. 

French physicist Marguerite Perey. AlP/PHOTO RESEARCHERS, INC. 

The element s name comes from the country France, and it was named in 1946 by Marguerite Perey (1909-1975), who discovered the element in 1939. Element 87 was predicted in 1871 by Mendeleev. He gave it the name eka-caesium. It was known first as actinium-K as a radioactive product of the decay of actinium, and it is the most unstable of the first 101 elements. Although francium occurs naturally, its short half-life means that there are only a few grams of the element at any time in the crust of the Earth. Because the longest lasting isotope of francium lasts only 22 minutes, it has no commercial uses. 

Actinium is one of the radioactive elements. It has the atomic number 89 and a weight of 227. In a rare form of decay discovered in 1939 by Mile. Marguerite Perey of the Curie Institute in Paris, actinium emits an alpha particle, losing two protons and thus becoming a new element with the atomic... 

The last discovery of an alkali metal occurred almost 80 years later. In 1939, Parisian physicist Marguerite Perey (1909-75) observed an unusual rate of radioactive decay in a sample of a salt of actinium (element 89). She managed to isolate the new element, showed that it was an alkali metal, and named it francium in honor of her native country, France. Because francium s longest-lived isotope has a half-life of only 21 minutes, francium is the rarest element below element 98 in the periodic table, which explains why francium was discovered much later than the other radioactive elements in that part of the table. 

French physicist Marguerite Perey is born on October 19 in Villemomble, France. 

Marguerite Perey dies on May 13 in Louveciennes, France. 1980 Fritz Strassmann dies on April 22 in Mainz, Germany. 

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. Debieme) 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 Perey, 1939) and promethium (J. A. Marinsky,... 

Since all isotopes of Fr are radioactive, it was not discovered until 1939 at the Curie Institute in Paris by Marguerite Perey, although the Russian chemist Dimitri Mendeleev predicted its existence. Its name derives from that of France, the country where it was discovered. 

Marguerite Perey did not invent any fundamentally new methods and did not indulge in any vague and complicated... 

Elements 85 and 87 fall into the region covered by the natural decay series and could therefore be expected to be fed by rare decay branches. As early as 1914, a particles were observed in carefully purified Ac (Z = 89), which implied the formation of element 87 (Meyer et al. 1914). However, the work of Marguerite Perey in 1939 is credited with the discovery of element 87 - the last discovery of a new element in nature (Perey 1939a, b). She proved that a 21 min P emitter ( 87) growing from Ac had chemical properties akin to cesium, and named the element francium (Fr). Element 85, astatine (At), the heaviest known halogen, was first produced artificially in 1940 as 85 (Ty2 = 7 h) by (a,2n) reaction on ° Bi (Corson et al. 1940a, b) before short-lived isotopes were found also in rare branches of the decay series. 

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