Francium
Alkali Metal
Francium (Fr) is a chemical element with atomic number 87, classified as a alkali metal. At room temperature it is a solid. It was discovered in 1939 by Marguerite Perey.
Properties
- Atomic number
- 87
- Atomic mass
- 223 u
- Category
- Alkali Metal
- Group
- 1
- Period
- 7
- Block
- s-block
- Electron configuration
- [Rn] 7s¹
- Phase at STP
- Solid
- Density
- 1.87 g/cm³
- Melting point
- 300 K (26.9 °C)
- Boiling point
- 950 K (676.9 °C)
- Electronegativity
- 0.7
- Atomic radius
- 348 pm
- Ionization energy
- 4.073 eV
- Discovery
- 1939 · Marguerite Perey
Common uses
Research only
Did you know?
Most unstable of the first 101 elements with half-life of 22 minutes.