Francium

\n \nCategory:Chemical elements \n\n\n \n\n\n\n \n\n\n\n\n\n\n\n \n \n \n\n \n\n \n\n \n\n \n\n\n\n \n\n \n\n \n \n\n \n\n \n\n\n\n \n\n \n\n\n\n\n\n \n\n\n\n\n\n \n\n \n\n \n\n\n\n\n\n\n

\n\n\n\n\n\n francium - radium Cs Fr   \n Full table \n
General
Name, Symbol, Number	Francium, Fr, 87
Series	Alkali metals
Group, Period, Block	1(IA), 7 , s
Density, Hardness	1870 kg/m3, no data
Appearance	metallic
Atomic properties
Atomic weight	(223) amu
Atomic radius	no data
Covalent radius	no data
van der Waals radius	no data
Electron configuration	[Rn]7s7s1
e- 's per energy level	2, 8, 18, 32, 18, 8, 1
Oxidation states (Oxide)	1 (strong base)
Crystal structure	Cubic body centered
Physical properties
State of matter	solid
Melting point	300 K (80.33 °F)
Boiling point	950 K (523.4 °F)
Molar volume	no data
Heat of vaporization	no data
Heat of fusion	no data
Vapor pressure	no data
Speed of sound	no data
Miscellaneous
Electronegativity	0.7 (Pauling scale)
Specific heat capacity	no data
Electrical conductivity	3 106/m ohm
Thermal conductivity	15 W/(m*K)
1st ionization potential	380 kJ/mol
Most stable isotopes
\n\n\n\n\n\n\n\n iso NA half-life DM DE MeV DP 222Fr {syn.} 14.2 m Beta- 2.033 222Ra 223Fr 100% 21.8 m Beta- alpha 1.149 5.430 221Ra 219At \n
SI units & STP are used except where noted.

\nFrancium is a chemical element in the periodic table that has the symbol Fr and atomic number 87. \nThis is a highly radioactive alkali metal that is found in uranium and thorium ores.

Table of contents

1 Notable characteristics 2 References 3 External links

Notable characteristics

\nThis element, which was named for France, was discovered in 1939 by Marguerite Perey of the Curie Institute in Paris. Francium is the heaviest alkali metal and occurs as a result of actinium's alpha decay and can be artificially made by bombarding thorium with protons. Even though it naturally occurs in uranium minerals, it has been estimated that there might be less than one ounce of francium in the crust of the earth at any one time. It is the most unstable element among the first 101 and has the highest equivalent weight of any element. There are 33 known isotopes of francium. At 22 minutes, the longest lived isotope of this element is Fr-223 which is a daughter isotope of Ac-227 and is the only isotope of francium that occurs naturally. All known isotopes of francium are highly unstable, therefore knowledge of the properties of this element only comes from radiochemical procedures. No research team has produced a weighable quantity of francium nor has this element been prepared or isolated, and probably never will be. Chemically, the properties of francium are closest to those of caesium.

References

\n*Los Alamos National Laboratory - Francium

External links

\n*WebElements.com - Francium\n*Chemical information for Francium\n*EnvironmentalChemistry.com - Francium