Element 58 · Cerium (Ce)

Cerium Bohr model: diagram and electrons per shell

The cerium Bohr model shows a cerium atom (Ce) as a small nucleus with its electrons circling it in 6 shells: 2 in shell K, 8 in shell L, 18 in shell M, 19 in shell N, 9 in shell O and 2 in shell P. This page has a rotating 3D cerium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the cerium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of cerium (Ce), a simplified picture of a single cerium atom. Its nucleus holds 58 protons, and a neutral cerium atom has 58 electrons, arranged around it in 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 19 in shell N, 9 in shell O and 2 in shell P).

Ce K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 194s² 4p⁶ 4d¹⁰ 4f¹ O · 95s² 5p⁶ 5d¹ P · 26s²

Cerium Bohr model diagram

Bohr model diagram of cerium: a nucleus of 58 protons with 58 electrons on 6 shells, 2 in shell K, 8 in shell L, 18 in shell M, 19 in shell N, 9 in shell O and 2 in shell P, each ring labelled with its shell letter. — The cerium 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, 19 in shell N, 9 in shell O and 2 in shell P).

Cerium electrons per shell

A neutral cerium atom has 58 electrons, one for each of its 58 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 19 in shell N, 9 in shell O and 2 in shell P.

Electrons in each shell of the cerium 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	19	32	4s² 4p⁶ 4d¹⁰ 4f¹
O	5	9	50	5s² 5p⁶ 5d¹
P	6	2	72	6s²

How the cerium Bohr model builds up, shell by shell

Watch the cerium 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, 19 in shell N, 9 in shell O and 2 in shell P) as it forms.

Animation of the cerium Bohr model being built: a nucleus of 58 protons appears first, then each shell grows in around it and takes its electrons, giving 58 electrons on 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 19 in shell N, 9 in shell O and 2 in shell P). — The cerium 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, 19 in shell N, 9 in shell O and 2 in shell P. Protons are red, neutrons yellow and electrons blue.

How to draw the cerium Bohr model

Find the atomic number. Cerium has atomic number 58, so a neutral atom has 58 protons and 58 electrons.
Draw the nucleus. Put a circle in the centre and write Ce in it. The 58 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, 19 in shell N, 9 in shell O and 2 in shell P.
Check the total. 2 + 8 + 18 + 19 + 9 + 2 = 58, the atomic number, so every electron is accounted for.

Atomic data for the cerium Bohr model

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

Identity

Symbol: Ce
Atomic number: 58
Atomic mass: 140.1161 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 5d¹ 4f¹
Shorthand: [Xe] 4f¹ 5d¹ 6s²
Electrons per shell: 2, 8, 18, 19, 9, 2
Outer-shell electrons: 2 in shell P

Ionisation energies

I₁: 534.4
I₂: 1050
I₃: 1949
I₄: 3547
I₅: 6325
I₆: 7490

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): 210
Empirical (pm): 185
Covalent (pm): 163

Electronegativity and electron affinity

Electronegativity (Pauling): 1.12
Electron affinity (kJ/mol): 55

Oxidation states

+3 +4

Charges the element commonly takes in compounds.

Physical properties, abundance and history of cerium

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

Physical properties

Phase at room conditions: Solid
Appearance: Silvery white
Melting point: 794.85°C (1068 K)
Boiling point: 3442.85°C (3716 K)
Density: 6.77 g/cm³
Thermal conductivity (W/m·K): 11.3
Specific heat (J/g·K): 0.192
Molar heat capacity (J/mol·K): 26.94
Heat of fusion (kJ/mol): 5.2
Heat of vaporisation (kJ/mol): 398

Abundance

Earth's crust (mg/kg): 66.5
Oceans (mg/L): 0

Discovery

Discovered by: Martin Heinrich Klaproth
Year: 1803

Common compounds

Cerium Ce
Ceric ammonium nitrate CeH8N8O18
Ceria CeO2
Cerous bromide Br3Ce
Cerium nitrate CeN3O9
Cerous 2-ethylhexanoate C24H45CeO6
Cerium trichloride CeCl3
Ceric sulfate CeO8S2

Compounds listed in the PubChem database.

Main isotopes of cerium

Isotopes of cerium share the same 58 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of cerium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
136	0.186 %	stable	2β⁺
138	0.251 %	stable	2β⁺
139	–	137.642 d	EC
140	88.449 %	stable	–
142	11.114 %	stable	α, 2β⁻
144	–	284.886 d	β⁻

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

More about cerium

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