87 - Francium alkali metal
Discovered by Marguerite Perey in 1939
- Atomic Radius (Å)
Francium is a chemical element with symbol Fr and atomic number 87. It used to be known as eka-caesium and actinium K. It is the second-least electronegative element, behind only caesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon.
Shell | Electrons | Orbitals |
---|---|---|
1 | 2 | 2 in 1s |
2 | 8 | 2 in 2s + 6 in 2p |
3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
4 | 32 | 2 in 4s + 6 in 4p + 10 in 4d + 14 in 4f |
5 | 18 | 2 in 5s + 6 in 5p + 10 in 5d |
6 | 8 | 2 in 6s + 6 in 6p |
7 | 1 | 1 in 7s |
223 u
Atomic Mass
950 K
Boiling Point
2.6 Å
Covalent Radius
1.87 g/cm³
Density
46.89
Electron Affinity
0.7
Electronegativity
4.07 eV
First Ionization Energy
300.15 K
Melting Point
7
Number of Shells
1
Electron Valency
87
Atomic Number
2, 8, 18, 32, 18, 8, 1
Electron Shell Occupations