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Francium

Francium

This article has been reviewed by the following Topic Editor: Peter Hughes

Previous Element: Radon

Next Element: Radium
87

Fr

223
Physical Properties
Color ---
Phase at Room Temp. solid
Density (g/cm3) ---
Hardness (Mohs) ---
Melting Point (K) 300.2
Boiling Point (K) ---
Heat of Fusion (kJ/mol) ---
Heat of Vaporization (kJ/mol) ---
Heat of Atomization (kJ/mol) 73
Thermal Conductivity (J/m sec K) ---
Electrical Conductivity (1/mohm cm) ---
Source Synthetic (U-235 decay)
Atomic Properties
Electron Configuration [RN]7s1
Number of Isotopes 41(0 natural)
Electron Affinity (kJ/mol) ---
First Ionization Energy (kJ/mol) 384
Second Ionization Energy (kJ/mol) ---
Third Ionization Energy (kJ/mol) ---
Electronegativity 0.7
Polarizability (Å3) 48.7
Atomic Weight 223
Atomic Volume (cm3/mol) ---
Ionic Radius2- (pm) ---
Ionic Radius1- (pm) ---
Atomic Radius (pm) ---
Ionic Radius1+ (pm) 194
Ionic Radius2+ (pm) ---
Ionic Radius3+ (pm) ---
Common Oxidation Numbers +1
Other Oxid. Numbers ---
Abundance
In Earth's Crust (mg/kg) ---
In Earth's Ocean (mg/L) ---
In Human Body (%) ---
Regulatory / Health
CAS Number 7440-73-5
OSHA Permissible Exposure Limit (PEL) No limit
OSHA PEL Vacated 1989 No limit
NIOSH Recommended Exposure Limit (REL) No limit
Sources:
University of Wisconsin General Chemistry
Mineral Information Institute
Jefferson Accelerator Laboratory
EnvironmentalChemistry.com
 

Citation

Adam Sibley (Lead Author);Peter Hughes (Topic Editor) "Francium". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth April 20, 2007; Last revised Date April 20, 2007; Retrieved May 23, 2013 <http://www.eoearth.org/article/Francium>

The Author

Adam Sibley E-scribe The Encyclopedia of Earth Adam Sibley is a sophmore at Boston University. He is currently majoring in Environmental Science. ... (Full Bio)

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