Francio
Francium (Fr) is a highly radioactive chemical element belonging to the Alkali metal group, with atomic number 87 and an atomic mass close to 223.0000 u (corresponding to its longest-lived isotope). This sheet describes its fundamental properties, periodic position and physical characteristics.
Identity
- Name: Francium
- Symbol: Fr
- Atomic number: 87
- Atomic mass: ≈ 223.0000 u (radioactive isotope)
Position in the periodic table
- Group: 1
- Period: 7
- Category: Alkali metal
Physico-chemical properties
- Standard state (20°C): Solid (predicted)
- Melting point: Low, around 20–30°C (estimated)
- Density: Approx. 2.5 g/cm³ (estimated)
- Electron configuration: [Rn] 7s¹
Scientific description
Francium is a highly radioactive alkali metal with the chemical symbol Fr and atomic number 87. It belongs to group 1 and period 7 of the periodic table. Due to the absence of stable isotopes, its atomic mass is given as that of its longest-lived isotope, ≈ 223 u. Because of its extreme radioactivity and scarcity, many of its physical properties are derived from theoretical estimates or extrapolations.
KODO: P6