68  Erbium

 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 Hf Ta W  Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
                                                      
       Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho[Er]Tm Yb Lu      
       Th Pa U  Np Pu Am Cm Bk Cf Es Fm Md No Lr      

+--------------------+
| 68  _____          |
|    | ____|_ __     |
|    |  _| | '__|    |
|    | |___| |       |
|    |_____|_|       |
|                    |
|       Erbium       |
|      167.26 u      |
+--------------------+

Electron Configuration: [Xe]6s2 4f12
Electronegativity:      1.24
Atomic Radius:          235 pm
Ionization Energy:      6.108 eV
Electron Affinity:      
Oxidation States:       3
Standard State:         Solid
Melting Point:          1802 K
Boiling Point:          3141 K
Density:                9.07 g/cm3
Family:                 Lanthanide
Year Discovered:        1843
Number of Neutrons:     99
Number of Protons:      68
Number of Electrons:    68
Number of Valence:      
Valency:                
Group:                  
Period:                 6
Shell:                  f-shell
Specific Heat:          0.168 J/g K
Radioactive:            0
Occurrence:             Natural
Source:                 Merging neutron stars