Element 29 · Copper (Cu)

Copper Bohr model: diagram and electrons per shell

The copper Bohr model shows a copper atom (Cu) as a small nucleus with its electrons circling it in 4 shells: 2 in shell K, 8 in shell L, 18 in shell M and 1 in shell N. This page has a rotating 3D copper Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the copper Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of copper (Cu), a simplified picture of a single copper atom. Its nucleus holds 29 protons, and a neutral copper atom has 29 electrons, arranged around it in 4 shells (2 in shell K, 8 in shell L, 18 in shell M and 1 in shell N).

Cu K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 14s¹

Copper Bohr model diagram

Bohr model diagram of copper: a nucleus of 29 protons with 29 electrons on 4 shells, 2 in shell K, 8 in shell L, 18 in shell M and 1 in shell N, each ring labelled with its shell letter. — The copper 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 and 1 in shell N).

Copper electrons per shell

A neutral copper atom has 29 electrons, one for each of its 29 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M and 1 in shell N.

Electrons in each shell of the copper 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	1	32	4s¹

How the copper Bohr model builds up, shell by shell

Watch the copper 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 and 1 in shell N) as it forms.

Animation of the copper Bohr model being built: a nucleus of 29 protons appears first, then each shell grows in around it and takes its electrons, giving 29 electrons on 4 shells (2 in shell K, 8 in shell L, 18 in shell M and 1 in shell N). — The copper 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 and 1 in shell N. Protons are red, neutrons yellow and electrons blue.

How to draw the copper Bohr model

Find the atomic number. Copper has atomic number 29, so a neutral atom has 29 protons and 29 electrons.
Draw the nucleus. Put a circle in the centre and write Cu in it. The 29 protons sit there with the neutrons.
Draw the shells. Sketch 4 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 and 1 in shell N.
Check the total. 2 + 8 + 18 + 1 = 29, the atomic number, so every electron is accounted for.

Atomic data for the copper Bohr model

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

Identity

Symbol: Cu
Atomic number: 29
Atomic mass: 63.5463 u
Family: Transition Metals
Position: group 11, period 4
Block: d-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰
Shorthand: [Ar] 3d¹⁰ 4s¹
Electrons per shell: 2, 8, 18, 1
Outer-shell electrons: 1 in shell N

Ionisation energies

I₁: 745.5
I₂: 1957.9
I₃: 3555
I₄: 5536
I₅: 7700
I₆: 9900
I₇: 13400
I₈: 16000

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): 145
Empirical (pm): 135
Covalent (pm): 112
Van der Waals (pm): 140

Electronegativity and electron affinity

Electronegativity (Pauling): 1.9
Electron affinity (kJ/mol): 119.235

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of copper

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

Physical properties

Phase at room conditions: Solid
Appearance: Red-orange metallic luster
Melting point: 1084.62°C (1357.77 K)
Boiling point: 2561.85°C (2835 K)
Density: 8.96 g/cm³
Thermal conductivity (W/m·K): 401
Specific heat (J/g·K): 0.385
Molar heat capacity (J/mol·K): 24.44
Heat of fusion (kJ/mol): 13.01
Heat of vaporisation (kJ/mol): 304.6

Abundance

Earth's crust (mg/kg): 60
Oceans (mg/L): 0

Discovery

Discovered by: Middle East
Year: Ancient

Common compounds

Copper Cu
Copper Sulfate CuO4S
Oxine-copper C18H12CuN2O2
Cupric Chloride Cl2Cu
Bis(D-gluconato-kappaO1,kappaO2)copper C12H22CuO14
Copper Naphthenate C21H36CuO4
Cuprous iodide CuI
Copper sulfate pentahydrate CuH10O9S

Compounds listed in the PubChem database.

Main isotopes of copper

Isotopes of copper share the same 29 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of copper: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
60	–	23.7 min	β⁺
61	–	3.343 h	β⁺
63	69.15 %	stable	–
64	–	12.7 h	β⁺, β⁻
65	30.85 %	stable	–
67	–	61.83 h	β⁻

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

More about copper

Copper on the periodic table – properties, isotopes, uses and the full copper page.
Transition Metals – all transition metal elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.