Element 67 · Holmium (Ho)

Holmium Bohr model: diagram and electrons per shell

The holmium Bohr model shows a holmium atom (Ho) as a small nucleus with its electrons circling it in 6 shells: 2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P. This page has a rotating 3D holmium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the holmium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of holmium (Ho), a simplified picture of a single holmium atom. Its nucleus holds 67 protons, and a neutral holmium atom has 67 electrons, arranged around it in 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P).

Ho K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 294s² 4p⁶ 4d¹⁰ 4f¹¹ O · 85s² 5p⁶ P · 26s²

Holmium Bohr model diagram

Bohr model diagram of holmium: a nucleus of 67 protons with 67 electrons on 6 shells, 2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P, each ring labelled with its shell letter. — The holmium Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P).

Holmium electrons per shell

A neutral holmium atom has 67 electrons, one for each of its 67 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P.

Electrons in each shell of the holmium Bohr model
Shell	Shell number (n)	Electrons	Most it can hold (2n²)	Subshells
K	1	2	2	1s²
L	2	8	8	2s² 2p⁶
M	3	18	18	3s² 3p⁶ 3d¹⁰
N	4	29	32	4s² 4p⁶ 4d¹⁰ 4f¹¹
O	5	8	50	5s² 5p⁶
P	6	2	72	6s²

How the holmium Bohr model builds up, shell by shell

Watch the holmium Bohr model come together: the nucleus first, then each shell in turn, from the innermost outwards, with its electrons joining the ring. The legend names every shell and counts its electrons, so you can read off the arrangement (2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P) as it forms.

Animation of the holmium Bohr model being built: a nucleus of 67 protons appears first, then each shell grows in around it and takes its electrons, giving 67 electrons on 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P). — The holmium Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P. Protons are red, neutrons yellow and electrons blue.

How to draw the holmium Bohr model

Find the atomic number. Holmium has atomic number 67, so a neutral atom has 67 protons and 67 electrons.
Draw the nucleus. Put a circle in the centre and write Ho in it. The 67 protons sit there with the neutrons.
Draw the shells. Sketch 6 shells as rings around the nucleus. A shell holds at most 2n² electrons: 2 in the first, 8 in the second, 18 in the third and 32 in the fourth.
Place the electrons. Fill from the inside out: 2 in shell K, 8 in shell L, 18 in shell M, 29 in shell N, 8 in shell O and 2 in shell P.
Check the total. 2 + 8 + 18 + 29 + 8 + 2 = 67, the atomic number, so every electron is accounted for.

Atomic data for the holmium Bohr model

The numbers behind the holmium Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).

Identity

Symbol: Ho
Atomic number: 67
Atomic mass: 164.9303 u
Family: Lanthanides
Position: period 6 of the f-block
Block: f-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹¹
Shorthand: [Xe] 4f¹¹ 6s²
Electrons per shell: 2, 8, 18, 29, 8, 2
Outer-shell electrons: 2 in shell P

Ionisation energies

I₁: 581
I₂: 1140
I₃: 2204
I₄: 4100

Energy to remove each electron in turn (kJ/mol). A sharp jump means the next electron comes from an inner shell.

Atomic radii

Calculated (pm): 226
Empirical (pm): 175
Covalent (pm): 166

Electronegativity and electron affinity

Electronegativity (Pauling): 1.23
Electron affinity (kJ/mol): 32.61

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of holmium

Bulk properties of holmium, how common it is, who discovered it and some of its compounds.

Physical properties

Phase at room conditions: Solid
Appearance: Silvery white
Melting point: 1460.85°C (1734 K)
Boiling point: 2599.85°C (2873 K)
Density: 8.79 g/cm³
Specific heat (J/g·K): 0.165
Molar heat capacity (J/mol·K): 27.15
Heat of vaporisation (kJ/mol): 301

Abundance

Earth's crust (mg/kg): 1.3
Oceans (mg/L): 0

Discovery

Discovered by: Marc Delafontaine
Year: 1878

Common compounds

Holmium Ho
Holmium chloride Cl3Ho
Holmium trifluoride F3Ho
Holmium nitride (HoN) HoN
Holmium iodide HoI3
Holmium chloride hexahydrate Cl3H12HoO6
Nitric acid, holmium(3+) salt (3:1) HoN3O9
Acetic acid, holmium(3+) salt (3:1) C6H9HoO6

Compounds listed in the PubChem database.

Main isotopes of holmium

Isotopes of holmium share the same 67 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of holmium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
156	–	56 min	β⁺
161	–	2.48 h	EC
163	–	4.57 ky	EC
165	100 %	stable	–
166	–	26.812 h	β⁻
167	–	3.1 h	β⁻

α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.

More about holmium

Holmium on the periodic table – properties, isotopes, uses and the full holmium page.
Lanthanides – all lanthanide elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.