Atomic Element Z = 68 • Lanthanide
Erbium (Er) — Atomic Data, Electron Shells & Reactions
Erbium (symbol Er, atomic number 68) has a standard atomic weight of 167.26 u and ground-state configuration [Xe] 4f12 6s2.
Atomic Number (Z)
68
IUPAC Symbol
Er
Standard Atomic Weight
167.26 g/mol
Period / Group / Block
6 / f-block / f-block
Condensed Electron Config
[Xe] 4f12 6s2
Full Subshell Config
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f12 5s2 5p6 6s2
Principal Shell Occupancy
[2, 8, 18, 30, 8, 2]
Pauling Electronegativity
1.24
First Ionization Energy
589 kJ/mol
Covalent Radius
189 pm
Melting Point
1802 K (1528.85 °C)
Boiling Point
3141 K (2867.85 °C)
Density
9.066 g/cm³
Oxidation States
+3
Er (Z=68) — Valence shell highlighted in vermilion