87Solid
Fr 223 Atomic mass · uAlkali metals
Francium
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.
Discovery 1939 (Marguerite Perey)
K2L8M18N32O18P8Q1
Physical properties
Values for the element in its standard state.
- Density
- Not available
- Melting point
- 300K
- Boiling point
- Not available
- Atomic radius
- Not available
- Bonding type
- Metallic
- Molar heat
- Not available
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 6 electrons; 3d, 10 electrons; 4s, 2 electrons; 4p, 6 electrons; 4d, 10 electrons; 5s, 2 electrons; 5p, 6 electrons; 4f, 14 electrons; 5d, 10 electrons; 6s, 2 electrons; 6p, 6 electrons; 7s, 1 electrons;
[Rn] represents 86 core electrons. The full view shows them explicitly.
87 electrons Orbital order preserved from source
- Electronegativity
- 0.7Pauling scale
- First ionization energy
- 380kJ/mol
- Electron affinity
- Not available
- Van der Waals radius
- Not available
Fr FranciumAtomic number 87
380kJ/mol
Atomic numberGaps indicate unavailable data
About francium
- Appearance
- Not recorded
- Discovery
- 1939 (Marguerite Perey)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.