Discovered By: Carl Gustaf Mosander
Discovery year: 1842

The following table showing some properties of Erbium(Er):

Table Example
Atomic number 68
Group n/a
Period 6
Block f
Atomic weight 167.259
Oxidation states +3
Ionic charge Er^3+
Electrons 68
Protons 68
Neutrons 99


Table Example
Electrons per shell K2 L8 M18 N30 O8 P2
Electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 4f^12
Atomic radius 226 pm
Covalent radius 189 pm
boiling point 2868°C
Melting point 1497°C
Neel point 82 K
Phase Solid
Fusion heat 19.9 kJ.mol^-1
Thermal expansion 1.22*10^-5 K^-1


Table Example
Vaporization heat 285 kJ.mol^-1
Color Silver
Brinell hardness 814 MPa
Bulk modulus 44 GPa
Density 9066 kg.m^-3
Liquid density 8860 kg.m^-3
Mohs hardness 2
Molar volume 1.845*10^-5 m^3.mol^-1
Poisson ratio 0.24
Shear modulus 20 GPa


Table Example
Sound speed 2830 m.s^-1
Vickers hardness 589 MPa
Young's modulus 70 GPa
Electrical type Conductor
Magnetic type Paramagnetic
Resistivity 8.6*10^-7 Ohm.m
Curie point 32 K
Electronegativity 1.24
Valence 3
Electron affinity 50 kJ.mol^-1
First ionization energy 589.3 kJ.mol^-1
Radioactive No
Neutron cross section 165 barn