68 - Erbium lanthanide
Discovered by Carl Gustaf Mosander in 1843
Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements on Earth. As such, it is a rare earth element which is associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden, where yttrium, ytterbium, and terbium were discovered.
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 | 30 | 2 in 4s + 6 in 4p + 10 in 4d + 12 in 4f |
| 5 | 8 | 2 in 5s + 6 in 5p |
| 6 | 2 | 2 in 6s |
167 u Atomic Mass
2.5 Å Atomic Radius
3.5k K Boiling Point
1.89 Å Covalent Radius
9.07 g/cm³ Density
30.1 Electron Affinity
1.24 Electronegativity
6.11 eV First Ionization Energy
1.8k K Melting Point
6 Number of Shells
68 Atomic Number
2, 8, 18, 30, 8, 2 Electron Shell Occupations