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Rosalind Franklin

MELTING POINT 27°C BOILING POINT 677°C DENSITY unknown MOST COMMON ION Fr+ [Pg.123]

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. [Pg.123]

Although there are a number of isotopes of francium, most decay very rapidly to other elements. Most isotopes with masses of 223 AMU and lower emit tt-particles (consisting of two protons and two neutrons) to become astatine. Some low mass francium isotopes can also undergo electron capture (the conversion of a proton to a neutron through the absorption of an electron) to become radon. Francium isotopes with masses of 220 AMU and higher can undergo /3-decay (the conversion of a neutron to a proton through the emission of an electron) to become radium. Francium-223 is the most stable isotope and has a half-life of 21.8 minutes. [Pg.123]

Naturally occurring francium is the product of a side reaction of the decay pathway of actinium. Actinium-227 generally undergoes /3-decay to produce thorium-227, but about 1 percent of the actinium emits an -particlc to form francium-223. Francium can be produced in the laboratory via proton bombardment of thorium and during oxygen 18 (0-18) bombardment of heated gold. [Pg.123]

Because of its extremely low abundance, short half-life, and high radioactivity, neither francium nor its compounds have economic applications. see also Alkali Metals Curie, Marie Sklodowska Mendeleev, Dimitri Radioactivity. [Pg.123]


Four-coordinate metal complex, 413 Franklin, Rosalind, 628 Frasch, Herman, 558... [Pg.688]

Franklin, Rosalind, and Gosling, Raymond G. (1953). Molecular Configuration in Sodium Thymonucleate. Nature 171 740-741. Available from . [Pg.125]

Franklin, Rosalind See Crick, Franos Harry Compton. [Pg.333]


See other pages where Rosalind Franklin is mentioned: [Pg.917]    [Pg.123]    [Pg.123]    [Pg.124]    [Pg.268]    [Pg.308]    [Pg.324]    [Pg.364]    [Pg.500]    [Pg.500]    [Pg.501]    [Pg.645]    [Pg.972]    [Pg.1325]    [Pg.296]    [Pg.300]    [Pg.274]   
See also in sourсe #XX -- [ Pg.1167 ]




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