Francium (Fr)
Francium is the chemical element with atomic number 87 and symbol Fr. It is a métal alcalin in period 7, group 1, with a standard atomic weight of 223 u.
Faits essentiels
- Z
- 87
- Atomic weight
- 223 u no stable isotope
- Category
- métal alcalin
- State at 298 K
- Solid
- Occurrence
- from decay, radioactive
- Discovered
- 1939
- CAS
- 7440-73-5
Propriétés mesurées
| Property | Value | Source |
|---|---|---|
| Electronegativity | 0.7 | National Center for Biotechnology Information (NIH) |
| Melting point | 300 K | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 348 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 376.3 kJ/mol | National Center for Biotechnology Information (NIH) |
| Electron affinity | 45.3 kJ/mol | National Center for Biotechnology Information (NIH) |
Configuration électronique
- Noble gas notation
- [Rn] 7s¹
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s¹
- Electrons per shell
- 2, 8, 18, 32, 18, 8, 1