Symbol: Er
Atomic Number: 68
Atomic Weight: 167.26
Element Classification: Rare Earth Element (Lanthanide Series)
Discovered By: Carl Mosander
Discovery Date: 1843 (Sweden)
Name Origin: Named after the Swedish town, Ytterby.
Density (g/cc): 9.06
Melting Point (K): 1802
Boiling Point (K): 3136
Appearance: Soft, malleable, silvery metal
Atomic Radius (pm): 178
Atomic Volume (cc/mol): 18.4
Covalent Radius (pm): 157
Ionic Radius: 88.1 (+3e)
Specific Heat (@20°C J/g mol): 0.168
Fusion Heat (kJ/mol): n/a
Evaporation Heat (kJ/mol): 317
Thermal Conductivity (@25°C W/m K):
Debye Temperature (K): n/a
Pauling Negativity Number: 1.24
First Ionizing Energy (kJ/mol): 581
Oxidation States: 3
Electronic Configuration: [Xe] 4f¹² 6s²
Lattice Structure: Hexagonal (HEX)
Lattice Constant (Å): 3.560
Lattice C/A Ratio: 1.570