Francium
Francium, the 87th element, is a radioactive member of the alkali group, with a
valence of +1. Its most stable isotope has an atomic mass of 223 amu, and its density
is unknown. Fr's electron levels are 2-8-18-32-18-8-1. It was discovered in 1939
by Marguerite Perey in France, and melts at a mere 26.85 degrees C... the temperature of a
about the temperature of a warm day. (80 degrees F) It boils at 676.85 degrees, and is the
most active metal, the most active element second to fluorine. Francium exists as a product
of the alpha disintegration of actinium. It can also be synthesized by bombarding thorium
with protons. In the entire crust of the earth, there is less than an ounce of Fr, and this
exists in uranium minerals. It is the most unstable of the first 101 elements, since the longest lived isotope, Francium
223, has a half life of 22 minutes. This "long-lived" isotope is the only natural one, the
properties of which most closely resemble cesium.
May 22, 1997
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