100Unknown
Fm 257 Atomic mass · uActinides
Fermium
Fermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.
Discovery 1952 (Lawrence Berkeley National Laboratory)
K2L8M18N32O30P8Q2
Physical properties
Values for the element in its standard state.
- Density
- Not available
- Melting point
- 1,800K
- Boiling point
- Not available
- Atomic radius
- Not available
- Bonding type
- Not recorded
- 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; 5f, 12 electrons; 7s, 2 electrons;
[Rn] represents 86 core electrons. The full view shows them explicitly.
100 electrons Orbital order preserved from source
- Electronegativity
- 1.3Pauling scale
- First ionization energy
- 627kJ/mol
- Electron affinity
- Not available
- Van der Waals radius
- Not available
Fm FermiumAtomic number 100
627kJ/mol
Atomic numberGaps indicate unavailable data
About fermium
- Appearance
- Not recorded
- Discovery
- 1952 (Lawrence Berkeley National Laboratory)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.