87
Fr
Francium
Alkali metal period 7 group 1 s-block discovered: 1939
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 87
- Atomic mass
- 223.01973 a.m.u.
- Electron configuration
- [Rn]7s1
- Electronegativity
- 0.7 on the Pauling scale
- Atomic radius
- 348 pm
- Ionization energy
- 3.9 eV
- Electron affinity
- 0.47 eV
- Oxidation states
- +1
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 300 K (26,85 °C)