Holmium (Ho)

Holmium properties

Atomic number

67

Atomic mass

164.93 u

Category

Lanthanide

Group

—

Period

6

Block

f-block

State at room temp.

Solid

Electronegativity

1.23

Melting point

1,734 K (1,460.8 °C)

Boiling point

2,993 K (2,719.8 °C)

Density

8.79 g/cm³

Valence electrons

2

Common charges

+3

Oxidation states

+3

Atomic radius

216 pm

Ionization energy

6.022 eV

Electron affinity

—

Radioactive

No, has stable isotopes

Discovered

1878

Holmium electron configuration

The electron configuration of Holmium (Ho) is [Xe] 4f11 6s2. Its 67 electrons are arranged in shells as 2, 8, 18, 29, 8, 2.

Protons, neutrons and electrons in Holmium

A neutral Holmium atom has 67 protons and 67 electrons. Most Holmium atoms have about 98 neutrons: the atomic mass rounded to 165, minus the atomic number 67.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Holmium have?

2

Holmium has 2 valence electrons in its outermost shell. As an f-block element, its 4f or 5f electrons can also take part in bonding.

See every element: Periodic table with valence electrons

Holmium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Holmium

164.93 g/mol

One mole of Holmium atoms (6.022 × 10²³ atoms) has a mass of 164.93 grams. Use this value to convert between grams and moles.

Holmium facts

• Holmium has one of the highest magnetic moments of any element and is used to focus fields in very strong magnets.
• Holmium (Ho) has atomic number 67 and is a solid at room temperature. It was discovered in 1878.

Position in the periodic table

Holmium is element 67, in period 6 of the periodic table. It is one of the Lanthanides in the f-block, shown in the rows below the main table.

All lanthanides

Uses of Holmium

Holmium is used in holmium lasers, which doctors use to break up kidney stones and treat enlarged prostates; their light is strongly absorbed by water, so it does not reach deep into tissue. Holmium oxide is a standard for checking the wavelength accuracy of spectrometers. Holmium also colors glass and cubic zirconia yellow or red, but its uses are limited by its rarity and cost.

Who discovered Holmium?

Swiss chemists Marc Delafontaine and Jacques-Louis Soret detected holmium spectroscopically in Geneva in 1878, and Swedish chemist Per Teodor Cleve independently separated it from erbium oxide in 1879. Cleve named it after Holmia, the Latin name for Stockholm.

Where does the name come from?

Holmium comes from Holmia, the Latin name for Stockholm, the Swedish capital. Per Teodor Cleve, a Stockholm native who identified the element in 1879, named it after his home city.

Discovery timeline