Francium

Francium (Fr)

Radioactive element, belongs to group 1 of the periodic table. Found in uranium and thorium ores. The 22 known isotopes are all radioactive, with the most stable being Fr-223. Its existence was confirmed in 1939 by Marguerite Perey.
Atomic Number87
Atomic Weight223
Mass Number199
Group1
Period7
Blocks
Protons87 p+
Neutrons112 n0
Electrons87 e-
Electron shell 087 francium.png Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
Atomic Volume
Covalent Radius
223 pm
Metallic Radius
Ionic Radius
180 pm
Crystal Radius
194 pm
Van der Waals radius
348 pm
Density
1.87 g/cm³
Boiling Point
950 K
Melting Point
300 K
Electrons per shell2, 8, 18, 32, 18, 8, 1
Electronegativity
0.7
Electrophilicity
0.724268882697 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
4.0727409 eV/particle
Heat of Vaporization
Heat of Fusion
Heat of Formation
Molar Heat Capacity
Specific Heat Capacity
Thermal Conductivity
Gas Basicity
Dipole Polarizability
317.8 a₀
C6 Dispersion Coefficient
Oxidation States1
Color
Silver
Crystal Structure (BCC)
Lattice Constant
Bulk Modulus
Electrical Resistivity
Electron Configuration[Rn] 7s1
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryAlkali metals, Alkali metals
CAS GroupIA
IUPAC GroupIA
Glawe Number7
Mendeleev Number6
Pettifor Number7
Geochemical ClassU/Th decay series
Goldschmidt Classsynthetic
Radioactivity
RadioactiveYes ☢️
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universena

Isotopes of Francium

Stable Isotopes
Unstable Isotopes
199Fr 200Fr 201Fr 202Fr 203Fr 204Fr 205Fr 206Fr 207Fr 208Fr 209Fr 210Fr 211Fr 212Fr 213Fr 214Fr 215Fr 216Fr 217Fr 218Fr 219Fr 220Fr 221Fr 222Fr 223Fr 224Fr 225Fr 226Fr 227Fr 228Fr 229Fr 230Fr 231Fr 232Fr

History

Francium was discovered in 1939 by Marguerite Perey of the Curie Institute in Paris, France. It was discovered when she was researching the radioactive decay of actinium-227. Marguerite Perey discovered that francium-223 is made naturally when actinium-227 emits an alpha-particle. Francium was named after France

DiscoverersMarguerite Derey
Discovery LocationFrance
Discovery Year1939
Name OriginNamed for France, the nation of its discovery.
Francium is highly radioactive
Francium was the last element discovered in nature, rather than by synthesis

Uses

Due to its instability and rarity, there are no commercial applications for francium. It has been used for research purposes in the fields of biology and of atomic structure. Its use as a potential diagnostic aid for various cancers has also been explored, but this application has been deemed impractical. Since its isotopes have such short half-lives there are no commercially significant compounds of francium.

Sources

Formed by decay of actinium. Chemical properties similar to cesium. Decays to radium or astatine.