Tin (Sn)
Element 50 · Post-transition metal · atomic mass 118.71 u · group 14, period 5
Electron shells: 2, 8, 18, 18, 4
Tin alloyed with copper produced bronze and with it a whole age of human technology. Today its biggest single use is the solder holding electronics together.
Below 13 °C tin slowly crumbles into a grey powder — "tin pest" has destroyed organ pipes and buttons.
- Atomic number
- 50
- Atomic mass
- 118.71 u
- Electron configuration
- [Kr] 5s² 4d¹⁰ 5p²
- Group · period · block
- 14 · 5 · p
- Oxidation states
- −4, +2, +4
- Electronegativity
- 1.96 (Pauling)
- Melting point
- 232 °C
- Boiling point
- 2,602 °C
- Density
- 7.287 g/cm³
- State at 20 °C
- Solid
- Appearance
- Silvery-white metal
- Discovered
- Known since antiquity
50 protons, and 50 electrons when neutral
IUPAC standard atomic weight
Carbon group
What Tin is used for
- Electronics solder
- Tin-plated steel food cans
- Bronze and pewter alloys
- Float glass manufacture
Atomic structure of Tin
A neutral tin atom has 50 protons and 50 electrons. Its most common isotope carries about 69 neutrons, which is where the mass number 119 comes from. Change the neutron count and you have a different isotope of tin; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 18, 18, 4. In orbital notation that is [Kr] 5s² 4d¹⁰ 5p², leaving 4 valence electrons in the outer shell — the ones that do the chemistry.
3D electron orbitals
See where Tin's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Tin sits in the periodic table
Metals to the right of the d-block. Softer, lower-melting and more brittle than the transition metals, with more covalent character in their bonding.
Discovery and naming
Tin has been known and used since antiquity, long before anyone could describe it as an element. Its name comes from Old English tin; symbol from Latin stannum, which is also why its symbol (Sn) does not match its English name.
Keep exploring
Atomic weight from IUPAC/CIAAW; physical properties from PubChem (US National Library of Medicine). Values that have never been measured are shown as “not measured” rather than estimated.
Related Calculators
Frequently Asked Questions
What is the atomic mass of Tin?
The standard atomic weight of Tin is 118.71 u, as published by IUPAC's Commission on Isotopic Abundances and Atomic Weights.
How many protons, neutrons and electrons does Tin have?
Tin has 50 protons, because the atomic number is the proton count and that is what makes an atom Tin at all. A neutral Tin atom has the same number of electrons, 50. The neutron count varies by isotope; the most common one has about 69, since 119 − 50 = 69.
What is the electron configuration of Tin?
The electron configuration of Tin is [Kr] 5s² 4d¹⁰ 5p². Its electrons are arranged 2, 8, 18, 18, 4 across 5 shells.
Is Tin a metal?
Yes. Tin is classified as a post-transition metal, on the metallic side of the table.
What group and period is Tin in?
Tin is in group 14 (the carbon group), period 5, in the p-block. The group is its column and the period is its row.
What is the charge of Tin?
Tin most commonly forms a 2+ or 4+ ion. It has 4 outer electrons available to lose. Across all its compounds it shows oxidation states of −4, +2, +4.
What is the melting point of Tin?
Tin melts at 232 °C and boils at 2,602 °C. That puts it in the solids at everyday temperatures.
What is Tin used for?
Electronics solder, Tin-plated steel food cans, Bronze and pewter alloys, Float glass manufacture. Tin alloyed with copper produced bronze and with it a whole age of human technology.
Who discovered Tin, and where does its name come from?
Tin (Sn) has been known and used since antiquity, long before anyone could describe it as an element. The name comes from Old English tin; symbol from Latin stannum.