Element 50 · Tin (Sn)

Tin Bohr model: diagram and electrons per shell

The tin Bohr model shows a tin atom (Sn) as a small nucleus with its electrons circling it in 5 shells: 2 in shell K, 8 in shell L, 18 in shell M, 18 in shell N and 4 in shell O. This page has a rotating 3D tin Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the tin Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of tin (Sn), a simplified picture of a single tin atom. Its nucleus holds 50 protons, and a neutral tin atom has 50 electrons, arranged around it in 5 shells (2 in shell K, 8 in shell L, 18 in shell M, 18 in shell N and 4 in shell O).

Sn K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 184s² 4p⁶ 4d¹⁰ O · 45s² 5p²

Tin Bohr model diagram

Bohr model diagram of tin: a nucleus of 50 protons with 50 electrons on 5 shells, 2 in shell K, 8 in shell L, 18 in shell M, 18 in shell N and 4 in shell O, each ring labelled with its shell letter. — The tin 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, 18 in shell N and 4 in shell O).

Tin electrons per shell

A neutral tin atom has 50 electrons, one for each of its 50 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 18 in shell N and 4 in shell O.

Electrons in each shell of the tin 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	18	32	4s² 4p⁶ 4d¹⁰
O	5	4	50	5s² 5p²

How the tin Bohr model builds up, shell by shell

Watch the tin 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, 18 in shell N and 4 in shell O) as it forms.

Animation of the tin Bohr model being built: a nucleus of 50 protons appears first, then each shell grows in around it and takes its electrons, giving 50 electrons on 5 shells (2 in shell K, 8 in shell L, 18 in shell M, 18 in shell N and 4 in shell O). — The tin 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, 18 in shell N and 4 in shell O. Protons are red, neutrons yellow and electrons blue.

How to draw the tin Bohr model

Find the atomic number. Tin has atomic number 50, so a neutral atom has 50 protons and 50 electrons.
Draw the nucleus. Put a circle in the centre and write Sn in it. The 50 protons sit there with the neutrons.
Draw the shells. Sketch 5 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, 18 in shell N and 4 in shell O.
Check the total. 2 + 8 + 18 + 18 + 4 = 50, the atomic number, so every electron is accounted for.

Atomic data for the tin Bohr model

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

Identity

Symbol: Sn
Atomic number: 50
Atomic mass: 118.7107 u
Family: Post-Transition Metals
Position: group 14, period 5
Block: p-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p²
Shorthand: [Kr] 4d¹⁰ 5s² 5p²
Electrons per shell: 2, 8, 18, 18, 4
Outer-shell electrons: 4 in shell O

Ionisation energies

I₁: 708.6
I₂: 1411.8
I₃: 2943
I₄: 3930.3
I₅: 7456

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): 145
Covalent (pm): 140
Van der Waals (pm): 217

Electronegativity and electron affinity

Electronegativity (Pauling): 1.96
Electron affinity (kJ/mol): 107.298

Oxidation states

−4 +2 +4

Charges the element commonly takes in compounds.

Physical properties, abundance and history of tin

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

Physical properties

Phase at room conditions: Solid
Appearance: Silvery-white (beta, β) or gray (alpha, α)
Melting point: 231.93°C (505.08 K)
Boiling point: 2601.85°C (2875 K)
Density: 7.365 g/cm³
Thermal conductivity (W/m·K): 66.8
Specific heat (J/g·K): 0.227
Molar heat capacity (J/mol·K): 27.112
Heat of fusion (kJ/mol): 7.07
Heat of vaporisation (kJ/mol): 296

Abundance

Earth's crust (mg/kg): 2.3
Oceans (mg/L): 0

Discovery

Year: Ancient

Common compounds

Dibutyltin dichloride C8H18Cl2Sn
Fentin acetate C20H18O2Sn
Dioctyltin dichloride C16H34Cl2Sn
Triphenyltin Chloride C18H15ClSn
Dibutyltin dilaurate C32H64O4Sn
Tributyltin Chloride C12H27ClSn
Dibutyltin oxide C8H18OSn
Tetraethyltin C8H20Sn

Compounds listed in the PubChem database.

Main isotopes of tin

Isotopes of tin share the same 50 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of tin: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
116	14.54 %	stable	–
117	7.68 %	stable	–
118	24.22 %	stable	–
119	8.59 %	stable	–
120	32.58 %	stable	–
124	5.79 %	stable	2β⁻

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

More about tin

Tin on the periodic table – properties, isotopes, uses and the full tin page.
Post-Transition Metals – all post-transition metal elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.