Holmium

Element 67 on the periodic table, symbol Ho, group 3, period 6.

Holmium is a chemical element with symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve.

Appearance: silvery white

Properties

Atomic Number: 67
Atomic Mass: 164.9303 u
Group: 3
Period: 6
Block: f-block
Category: Lanthanide
State at 25 °C: Solid
Melting Point: 1,734 K · 1,460.9 °C
Boiling Point: 2,873 K · 2,599.9 °C
Density: 8.79 g/cm³
Atomic Radius: 175 pm
Electronegativity: 1.23
Oxidation States: +3
Abundance in Crust: 1.3 mg/kg
Discovered: 1878
Discovered By: Marc Delafontaine

Electron Configuration

[Xe] 4f11 6s2

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f11

Ionisation Energies (kJ/mol)

1. 581
2. 1,140
3. 2,204
4. 4,100

Elements near Holmium

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.