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50 Sn 118.710(7)

Tin

Poor metal
Symbol Sn
Atomic Number 50
Atomic Weight 118.710(7)
CAS Registry ID 7440-31-5
Group Name (none)
Period Number 5
Block p-block
State at STP Solid

Description

Sample of Tin ⌕ Enlarge Image

Tin is one of the poor metals that has a shiny silver grey color in its natural solid state. Tin is very malleable and will emit a crackling sound when it is bent due to its crystalline structure. Tin has an atomic weight of 118.710, a melting point of 449.47 °F, and a boiling point of 4716 °F. Some common uses of tin include: as a plating for steel containers used for food preservation, as an alloy in a variety of metals, as a component in solders, and in the production of window glass.

Isolation

The isolation of tin is necessary to separate tin from deposits that it occurs in. This process is performed on a large scale commercial basis.

Tin ⌕ Enlarge Image

The main source of tin for isolation purposes comes from placer mining. Placer mining is the mining of alluvial deposits for minerals; it can be performed using water pressure, open-pit mining, or through excavation. The mineral cassiterite is a tin oxide mineral and is the mineral that is used most for tin isolation. Once ore that contains tin is collected, the tin isolation process begins with removing the ore through a reduction reaction using coal in a reverberatory furnace; in this furnace, the tin ore is heated in a private compartment that allows it to come in contact with the combustion gases of the coal but not the coal itself. The tin is removed easily from the ore in this manner, and it is believed that tin removal from ore through coal was used by ancient peoples. Since cassiterite is a tin oxide, SnO2, the only product from this type of isolation process using coal is pure tin and carbon monoxide.

General

NameTin
SymbolSn
Number50
Chemical seriesPoor metal
Group14
Period5
Blockp
Appearancesilvery lustrous gray
Standard atomic weight118.710(7) g·mol⁻¹
Electron configuration[Kr] 4d10 5s2 5p2
Electrons per shell2, 8, 18, 18, 4

Atomic Properties

Crystal structuretetragonal
Oxidation states4, 2 (amphoteric oxide)
Electronegativity1.96 (scale Pauling)
Ionization energies1st:  708.6  kJ·mol−1
2nd:  1411.8  kJ·mol−1
3rd:  2943.0  kJ·mol−1
Atomic radius145 pm
Atomic radius (calc.)145 pm
Covalent radius141 pm
Van der Waals radius217 pm

Physical Properties

Phasesolid
Density (near r.t.)(white) 7.265  g·cm−3
Liquid density at m.p.6.99  g·cm−3
Melting point505.08 K (231.93 °C, 449.47 °F)
Boiling point2875 K (2602 °C, 4716 °F)
Critical point
Heat of fusion(white) 7.03  kJ·mol−1
Heat of vaporization(white) 296.1  kJ·mol−1
Heat capacity(25 °C) (white) 27.112  J·mol−1·K−1

Miscellaneous

Magnetic ordering
Electrical resistivity(0 °C) 115 nΩ·m
Thermal conductivity(300 K) 66.8  W·m−1·K−1
Thermal expansion(25 °C) 22.0  µm·m−1·K−1
Speed of sound (thin rod)(r.t.) (rolled) 2730  m·s−1
Young's modulus50 GPa
Shear modulus18 GPa
Bulk modulus58 GPa
Poisson ratio0.36
Mohs hardness1.5
Vickers hardness
Brinell hardness51 MPa