87 · Fr
Francium
Identified by Perey in 1939.
Identity
- Atomic number
- 87
- Symbol
- Fr
- Canonical name
- Francium
- Category
- alkali metal
- Group
- 1
- Period
- 7
- Block
- s
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- [223] No standard atomic weight. The number shown is the conventional mass number used in tables, not a measured mass in u.
- Electron configuration
- [Rn] 7s1
- Electrons per shell
- 2, 8, 18, 32, 18, 8, 1
- Standard state
- solid
- Density
- 1.87 g/cm³
- Melting point
- 300 K
- Boiling point
- 950 K
- Electronegativity
- 0.79 Pauling
- First ionization energy
- 380 kJ/mol
- Electron affinity
- 46.89 kJ/mol
Notable isotopes
This summary is not an inventory of every isotope.
Conventional mass number: 223
History
Actinium K
Discovery · confirmed · 1939
Perey identifies francium as a decay product of actinium, at the Radium Institute.
Etymology
- Theme
- country
- Language
- latin
- Root
- Francia
- Meaning
- France
Scientists
Places and institutions
- Paris — historical setting : France — present country : France
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements