chemical element with symbol Sn and atomic number 50

Tin is a chemical element with symbol Sn (for Latin: stannum) and atomic number 50. It is in Group 14 on the periodic table. It has ten isotopes that are not radioactive, which is more than any other element.

Tin, 00Sn
Allotropessilvery-white, β (beta); gray, α (alpha)
Appearancesilvery-white (beta, β) or gray (alpha, α)
Standard atomic weight Ar°(Sn)
Tin in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


Groupgroup 14 (carbon group)
Periodperiod 5
Block  p-block
Electron configuration[Kr] 4d10 5s2 5p2
Electrons per shell2, 8, 18, 18, 4
Physical properties
Phase at STPsolid
Melting point505.08 K ​(231.93 °C, ​449.47 °F)
Boiling point2875 K ​(2602 °C, ​4716 °F)
Density (near r.t.)white, β: 7.265 g/cm3
gray, α: 5.769 g/cm3
when liquid (at m.p.)6.99 g/cm3
Heat of fusionwhite, β: 7.03 kJ/mol
Heat of vaporizationwhite, β: 296.1 kJ/mol
Molar heat capacitywhite, β: 27.112 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1497 1657 1855 2107 2438 2893
Atomic properties
Oxidation states−4, −3, −2, −1, 0,[2] +1,[3] +2, +3,[4] +4 (an amphoteric oxide)
ElectronegativityPauling scale: 1.96
Ionization energies
  • 1st: 708.6 kJ/mol
  • 2nd: 1411.8 kJ/mol
  • 3rd: 2943.0 kJ/mol
Atomic radiusempirical: 140 pm
Covalent radius139±4 pm
Van der Waals radius217 pm
Color lines in a spectral range
Spectral lines of tin
Other properties
Natural occurrenceprimordial
Crystal structuretetragonal
Tetragonal crystal structure for tin

white (β)
Crystal structureface-centered diamond-cubic
Diamond cubic crystal structure for tin

gray (α)
Speed of sound thin rod2730 m/s (at r.t.) (rolled)
Thermal expansion22.0 µm/(m⋅K) (at 25 °C)
Thermal conductivity66.8 W/(m⋅K)
Electrical resistivity115 nΩ⋅m (at 0 °C)
Magnetic orderinggray: diamagnetic[5]
white (β): paramagnetic
Molar magnetic susceptibility(white) +3.1·10−6 cm3/mol (298 K)[6]
Young's modulus50 GPa
Shear modulus18 GPa
Bulk modulus58 GPa
Poisson ratio0.36
Brinell hardness50–440 MPa
CAS Number7440-31-5
Discoveryaround 3500 BC
Symbol"Sn": from Latin stannum
Isotopes of tin
Main isotopes[7] Decay
abun­dance half-life (t1/2) mode pro­duct
112Sn 0.970% stable
114Sn 0.66% stable
115Sn 0.34% stable
116Sn 14.5% stable
117Sn 7.68% stable
118Sn 24.2% stable
119Sn 8.59% stable
120Sn 32.6% stable
122Sn 4.63% stable
124Sn 5.79% stable
126Sn trace 2.3×105 y β 126Sb
 Category: Tin
| references

Properties change

Physical properties change

Alpha(α) and beta(β) forms of tin

Tin is a silver, somewhat soft metal. It is a post-transition metal. Its melting point is 231.93°C and its boiling point is 2602 °C. It can melt easily in a flame. It is malleable. It makes a crackling sound called tin cry when a piece of it is bent. Tin has more non-radioactive isotopes than any other element.

Tin is found in two allotropes: alpha-tin and beta-tin. Alpha-tin is a brittle, dull, powdery, semimetallic form of tin. It is made when very pure tin is cooled. Beta-tin is the normal shiny, soft, conductive, metallic form. It is made at higher temperatures. The decay of tin by turning from beta-tin to alpha-tin is called tin pest. Alpha-tin is not wanted in many places. When small amounts of other elements like antimony are added, the tin cannot change into alpha-tin. When alpha-tin is heated, it changes into beta-tin.

Tin can be hardened by adding antimony or copper, as well as some other elements. These also make it resistant to tin pest. Tin can also be made very shiny. Tin can make an alloy with copper called bronze.

Chemical properties change

Tin resists many corrosive substances and is often used to protect other metals. Salt water and fresh water do not affect tin. It dissolves in strong acids to make tin salts. It reacts with some strong bases.

Chemical compounds change

Tin forms chemical compounds in two oxidation states: +2 and +4. +2 compounds are reducing agents. Some of them are colorless while others are colored. +4 compounds are more unreactive and act more covalent.

Tin burns in air to make tin(IV) oxide, which is white. Tin(IV) oxide dissolves in acids to make other tin(IV) compounds. Tin(IV) chloride is a colorless fuming liquid when anhydrous and a white solid when hydrated. It easily reacts with water to make tin(IV) oxide and an acid again.

Tin reacts with hydrohalic acids to make tin(II) halides. For example, tin(II) chloride is made when tin dissolves in hydrochloric acid. Tin(IV) halides are made when tin reacts with the halogens. Tin(IV) chloride is made when tin reacts with chlorine. Tin(II) sulfate is different as it does not oxidize to tin(IV) sulfate. Tin(II) oxide is a blue-black solid that burns in air to make tin(IV) oxide.

+2 compounds

+2 compounds are reducing agents. They are about as common as +4 compounds. Some are colorless, while others are colored.

+4 compounds

+4 compounds are unreactive. Some are colorless.

Occurrence change


Tin is not found as a metal in the ground. It is normally in the form of cassiterite. Cassiterite is a mineral containg tin(IV) oxide. The cassiterite is normally found downstream of the cassiterite deposit when it is by a stream or river. Tin is also found in some complicated sulfide minerals.

Tin does not have any major job in the human body.

Preparation change

Tin is made by heating cassiterite with carbon in a furnace. China is the biggest maker of tin.

History change

People discovered tin long ago and used it with other metals. When copper and tin are mixed together, bronze is made. Bronze was important in the past, because it was one of the strongest metals available, which meant it was useful in weapons and tools. Bronze changed the world when it was first invented, starting the Bronze Age. People organized themselves more, because making tools from bronze was harder than making them from rock and wood like they did before.

Uses change

Pewter plate
Tin solder without lead

Tin is used in solder. Solder used to contain a mixture of lead and tin. Now the lead is removed because of its toxicity.

Tin is also used to make pewter, which is mainly tin mixed with a small amount of copper and other metals. Babbitt metal also has tin in it. Tin is used to coat several metals, like lead and steel. Tin plated steel containers are used to store foods. The pipes on a pipe organ are made of tin. Tin foil was used before aluminium foil. Tin was one of the first superconductors to be found. Organotin compounds are more common than almost any other organometal compound. They are used in some PVC pipes to stop them from decaying. Organotin compounds are toxic, though.

Safety change

Tin is not toxic, but tin compounds are very toxic to marine life. They are a little toxic to humans.

Sources change

  1. "Standard Atomic Weights: Tin". CIAAW. 1983.
  2. "New Type of Zero-Valent Tin Compound". Chemistry Europe. 27 August 2016.
  3. "HSn". NIST Chemistry WebBook. National Institute of Standards and Technology. Retrieved 23 January 2013.
  4. "SnH3". NIST Chemistry WebBook. National Institure of Standards and Technology. Retrieved 23 January 2013.
  5. Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  6. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  7. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  8. "SnH3". NIST Chemistry WebBook. National Institure of Standards and Technology. Retrieved 23 January 2013.
  9. "HSn". NIST Chemistry WebBook. National Institute of Standards and Technology. Retrieved 23 January 2013.