Fr
Francium
FRANCIUM
ALKALI METAL
| Atomic number: | 87 |
| Group numbers: | 1 |
| Period: | 7 |
| Electronic configuration: | [Rn] 7s1 |
| Formal oxidation number: | +1 |
| Electronegativities: | 0.7 |
| Atomic radius / pm: | 282 |
| Relative atomic mass: | - |
Francium was discovered by Marguerite Perey (FR) in 1939. Named for France, the nation of its discovery. It is a highly rare and unstable, radioactive metal. Its chemical properties are similar to caesium. Francium is formed from the decay of actinium. It can be produced by bombarding radium or astatine with neutrons. Since its isotopes have such short half-lives there are no commercially significant compounds of francium.
| Density / g dm-3: | - | |
| Molar volume / cm3mol-1: | - | |
| Electrical resistivity / µΩcm: | - | (20 °C) |
| Thermal conductivity / W m-1K-1: | 15 |
| Melting point / °C: | 27 |
| Boiling point / °C: | 677 |
| Heat of fusion / kJ mol-1: | - |
| Heat of vaporization / kJ mol-1: | - |
| Heat of atomization / kJ mol-1: | 75 |
| First ionization energy / kJ mol-1: | 392.96 |
| Second ionization energy / kJ mol-1: | - |
| Third ionization energy / kJ mol-1: | - |
| in the atmosphere / ppm: | - |
| in the Earth's crust / ppm: | - |
| in the oceans / ppm: | - |
| Crystal structure: | unknown structure |
| Unit-cell dimensions / pm: | - |
| Space group: | - |
| Isotope | Relative atomic mass | Mass percent (%) |
|---|---|---|
| 212Fr | 211.996 23(6) | * |
| 222Fr | 222.0176(2) | * |
| 223Fr | 223.019 74(2) | * |
| Balanced half-reaction | Eo / V | |
|---|---|---|
Citing this page:
Generalic, Eni. "Francium." EniG. Periodic Table of the Elements. KTF-Split, 13 Feb. 2025. Web. {Date of access}. <https://www.periodni.com/fr.html>.
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