100 - Fermium actinide
Discovered by Lawrence Berkeley Laboratory in 1953
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.
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
57-71 La-Lu Lanthanides
89-103 Ac-Lr Actinides
| 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
34 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