Francium information, including Technical Data, Safety Data and its high purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.
 Francium is formerly known as eka-caesium and actinium K. It is the second rarest naturally occurring element, the first being Astatine. Francium has the lowest electronegativities of all known elements and it was the last element discovered in nature. Outside of the laboratory, only trace amounts of francium can be found in uranium and thorium ores. Out of all of the naturally occurring elements, francium is the most unstable. Due to its rarity and instability, commercial applications for francium do not exist.
Francium is a S-Block, Group 1, Period 7 element. The number of electrons in each of Francium's shells is 2,8,18,32,18,8,1 and its electronic configuration is 1s2 2s2p6 3s2p6d10 4s2p6d10f14 5s2p6d10 6s2p6 7s1. In its elemental form francium's CAS number is 7440-73-5. The francium atom has a radius of 270.pm and
it's Van der Waals radius is 348.pm.
Francium was discovered by Marguerite Perey of the Curie Institute in Paris, France in 1939 although its existence was predicted by Mendeleev during the 1870's.
 Francium |
 Francium |
 Francio |
 Frâncio |
 Francio |
 Francium |
Abundance. The following table shows the abundance of francium and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope.
| Isotope |
Atomic Mass |
% Abundance on Earth |
| Fr-210 |
209.99640 |
- |
| Fr-211 |
210.99553 |
- |
| Fr-212 |
211.99618 |
- |
Energy. The ionization energy for francium (the least required energy to release a single electron from the atom in it's ground state in the gas phase) is stated in the following table:
| 1st Ionization Energy |
384 kJ mol-1 |
| 2nd Ionization Energy |
kJ mol-1
|
| 3rd Ionization Energy |
kJ mol-1
|
Conductivity. As to francium's electrical and thermal conductivity, the electrical conductivity measured in terms of electrical resistivity @ 20 ºC is - µOcm and its electronegativities (or its ability to draw electrons relative to other elements) is 0.7. The thermal conductivity of francium is 0.15 W/cmK.
Thermal Properties. The melting point and boiling point for francium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
| Heat of Fusion |
2 kJ mol-1 |
| Heat of Vaporization |
64 kJ mol-1 |
| Heat of Atomization |
73 kJ mol-1 |
Recent Research & Development for Francium
Collinear laser spectroscopy of francium using online rubidium vapor neutralization and amplitude modulated lasers.
Sell JF, Gulyuz K, Sprouse GD.
Rev Sci Instrum. 2009 Dec;80(12):123108.PMID: 20059132 [PubMed]
Relativistic coupled cluster (RCC) computation of the electric dipole moment enhancement factor of francium due to the violation of time reversal symmetry.
Mukherjee D, Sahoo BK, Nataraj HS, Das BP.
J Phys Chem A. 2009 Nov 12;113(45):12549-57.PMID: 19795824 [PubMed]
Accurate measurements of transition frequencies and isotope shifts of laser-trapped francium.
Sanguinetti S, Calabrese R, Corradi L, Dainelli A, Khanbekyan A, Mariotti E, de Mauro C, Minguzzi P, Moi L, Stancari G, Tomassetti L, Veronesi S.
Opt Lett. 2009 Apr 1;34(7):893-5.PMID: 19340162 [PubMed]
Ground electronic states of RbO2+, CsO2+ and FrO2: the ionization energies of RbO2 and CsO2.
Lee EP, Wright TG.
J Phys Chem A. 2005 Apr 14;109(14):3257-61.PMID: 16833657 [PubMed - indexed for MEDLINE]
X-ray and neutron scattering studies of the hydration structure of alkali ions in concentrated aqueous solutions.
Ansell S, Barnes AC, Mason PE, Neilson GW, Ramos S.
Biophys Chem. 2006 Dec 1;124(3):171-9. Epub 2006 May 11.PMID: 16815625 [PubMed - indexed for MEDLINE]
Efforts to control the errant products of a targeted in vivo generator.
Jaggi JS, Kappel BJ, McDevitt MR, Sgouros G, Flombaum CD, Cabassa C, Scheinberg DA.
Cancer Res. 2005 Jun 1;65(11):4888-95.PMID: 15930310 [PubMed - indexed for MEDLINE]Free Article
Lifetime measurement of the 9s level of atomic francium.
Aubin S, Gomez E, Orozco LA, Sprouse GD.
Opt Lett. 2003 Nov 1;28(21):2055-7.PMID: 14587813 [PubMed]
Selectivity of calix[4]arene-bis(benzocrown-6) in the complexation and transport of francium ion.
Haverlock TJ, Mirzadeh S, Moyer BA.
J Am Chem Soc. 2003 Feb 5;125(5):1126-7.PMID: 12553788 [PubMed]
[Ultrasound densitometry of the heel bone in the diagnosis of osseous tissue metabolic abnormalities in patients with rheumatoid arthritis].
Iakimenko EA, Dets' VV, Tbileli VV.
Lik Sprava. 2001 Sep-Dec;(5-6):185-6. Russian. PMID: 11881371 [PubMed - indexed for MEDLINE]
Breakthrough of 225Ac and its radionuclide daughters from an 225Ac/213Bi generator: development of new methods, quantitative characterization, and implications for clinical use.
Ma D, McDevitt MR, Finn RD, Scheinberg DA.
Appl Radiat Isot. 2001 Nov;55(5):667-78.PMID: 11573800 [PubMed - indexed for MEDLINE]
7S(1/2) ? 9S(1/2) two-photon spectroscopy of trapped francium.
Simsarian JE, Shi W, Orozco LA, Sprouse GD, Zhao WZ.
Opt Lett. 1996 Dec 1;21(23):1939-41.PMID: 19881852 [PubMed - in process]
Calculation of energy levels, E1 transition amplitudes, and parity violation in francium.
Dzuba VA, Flambaum VV, Sushkov OP.
Phys Rev A. 1995 May;51(5):3454-3461. No abstract available. PMID: 9912005 [PubMed - as supplied by publisher]
Static multipole polarisabilities and second-order Stark shift in francium.
Khan F, Khandelwal GS, Wilson JW.
J Phys B At Mol Opt Phys. 1988;21:731-7.PMID: 11539071 [PubMed - indexed for MEDLINE]
Neuropsychiatric manifestations of alkali metal deficiency and excess.
Yung CY.
Pharmacol Biochem Behav. 1984;21 Suppl 1:71-5. Review.PMID: 6395136 [PubMed - indexed for MEDLINE]
[The action of various substances on the function of the Starling rat heart-lung preparation].
Carminati GM, D'Atri G.
Arch Int Pharmacodyn Ther. 1968 Nov;176(1):134-48. Italian. No abstract available. PMID: 5709779 [PubMed - indexed for MEDLINE]
Ion exchange procedures. VII. Separation of alkali metal ions.
Nelson F, Michelson DC, Phillips HO, Kraus KA.
J Chromatogr. 1965 Oct;20(1):107-21. No abstract available. PMID: 5866088 [PubMed - indexed for MEDLINE]
[Chromatographic separation of francium].
PEREY M, ADLOFF JP.
C R Hebd Seances Acad Sci. 1953 Mar 16;236(11):1163-5. Undetermined Language. No abstract available. PMID: 13059958 [PubMed - indexed for MEDLINE]
[Fixation of element 87, francium, in experimental sarcoma of rat].
PEREY M, CHEVALLIER A.
C R Seances Soc Biol Fil. 1951 Aug;145(15-16):1208-11. Undetermined Language. No abstract available. PMID: 14905691 [PubMed - indexed for MEDLINE]
[Distribution of element 87, francium, in tissues of the normal rat].
PEREY M, CHEVALLIER A.
C R Seances Soc Biol Fil. 1951 Aug;145(15-16):1205-7. Undetermined Language. No abstract available. PMID: 14905690 [PubMed - indexed for MEDLINE]
Research updated 8/8/2011 |
