Francium

Source of the photo
http://www.webelements.com/francium/
Author of the description
Gruiz Katalin

Atomic number

87

Atomic mass

233 g.mol -1

Electronegativity

0.7

Density

1,87 g.cm-3

Melting point

27 °C

Boiling point

677 °C

Vanderwaals radius

unknown

Ionic radius

unknown

Isotopes

34

Electronic shell

[ Rn ] 7s1

Energy of first ionisation

375 kJ.mol -1

Discovered by

Marguerite Perey in 19

 Francium is extremely rare. Because of this its chemical and physical properties are not known. It has been studied by radiochemical techniques, which show that its most stable state is the ion Fr+. Francium is the least electronegative of all the known elements.

Applications

No use has been found for what little francium can be produced.