100 - Fermium actinide
Discovered by Lawrence Berkeley Laboratory in 1953
- Atomic Radius (Å)
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.
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 | 30 | 2 in 5s + 6 in 5p + 10 in 5d + 12 in 5f |
6 | 8 | 2 in 6s + 6 in 6p |
7 | 2 | 2 in 7s |
257 u
Atomic Mass
9.7 g/cm³
Density
33.96
Electron Affinity
1.3
Electronegativity
6.5 eV
First Ionization Energy
7
Number of Shells
100
Atomic Number
2, 8, 18, 32, 30, 8, 2
Electron Shell Occupations