TIN

CARBON GROUP

Atomic number:	50
Group numbers:	14
Period:	5
Electronic configuration:	[Kr] 4d¹⁰ 5s² 5p²
Formal oxidation number:	+2 +4
Electronegativities:	1.96
Atomic radius / pm:	140.5
Relative atomic mass:	118.710(7)

Tin has been known since ancient times. The origin of the name comes from the Latin word stannum meaning tin. It is a silvery-white, soft, malleable and ductile metal that ressist oxygen and water but dissolves in acids and bases. Exposed surfaces form oxide film. Organic tin compounds may be highly toxic. Tin is principally found in the ore cassiterite (SnO2) and stannine (Cu2FeSnS4). It is used as a coating for steel cans since it is non-toxic and non-corrosive, also in solder (33%Sn:67%Pb), bronze (20%Sn:80%Cu) and pewter. Stannous fluoride (SnF2), a compound of tin and fluorine is used in some toothpaste. The price of 99.8 % pure tin shot is 57.70 € for 500 g.

PHYSICAL PROPERTIES
Density / g dm^-3:	5750	(alpha, 273 K)
	7310	(beta, 273 K)
	6973	(m.p.)
Molar volume / cm³mol^-1:	20.65	(alpha, 273 K)
	16.24	(beta, 273 K)
	17.02	(m.p.)
Electrical resistivity / µΩcm:	11	(20 °C)

THERMAL PROPERTIES
Thermal conductivity / W m^-1K^-1:	66.6
Melting point / °C:	231.928
Boiling point / °C:	2602
Heat of fusion / kJ mol^-1:	7.2
Heat of vaporization / kJ mol^-1:	296.2
Heat of atomization / kJ mol^-1:	302

IONIZATION ENERGIES
First ionization energy / kJ mol^-1:	708.58
Second ionization energy / kJ mol^-1:	1411.81
Third ionization energy / kJ mol^-1:	2943.07

ABUNDANCE OF ELEMENT
in the atmosphere / ppm:	-
in the Earth's crust / ppm:	2.5
in the oceans / ppm:	0.003

CRYSTALLOGRAPHIC DATA
Crystal structure:	body-centered tetragonal
Unit-cell dimensions / pm:	a=583.16, c=318.13
Space group:	I4₂/amd

ISOTOPES
Isotope	Relative atomic mass	Mass percent (%)
¹¹²Sn	111.904821(5)	0.97(1)
¹¹⁴Sn	113.902782(3)	0.65(1)
¹¹⁵Sn	114.903346(3)	0.34(1)
¹¹⁶Sn	115.901744(3)	14.53(1)
¹¹⁷Sn	116.902954(3)	7.68(7)
¹¹⁸Sn	117.901606(3)	24.23(11)
¹¹⁹Sn	118.903309(3)	8.59(4)
¹²⁰Sn	119.902197(3)	32.59(10)
¹²²Sn	121.903440(3)	4.63(3)
¹²⁴Sn	123.905275(1)	5.79(5)

REDUCTION POTENTIALS
Balanced half-reaction	E^o / V
Sn⁴⁺ + 2e^- → Sn²⁺	+0.154
Sn⁴⁺ + 2e^- → Sn²⁺	+0.14	(1 mol dm^-3 HCl)
Sn⁴⁺ + 4e^- → Sn(s)	+0.01
Sn²⁺ + 2e^- → Sn(s)	- 0.136
Sn²⁺ + 2e^- → Sn(s)	- 0.16	(1 mol dm^-3 HClO₄)
SnO₃^2- + 3H⁺ + 2e^- → HSnO₂^- + H₂O	+0.374
SnO₃^2- + 6H⁺ + 2e^- → Sn²⁺ + 3H₂O	+0.844
HSnO₂^- + 3H⁺ + 2e^- → Sn(s) + 2H₂O	+0.333
Sn(s) + 4H⁺ + 4e^- → SnH₄(g)	- 1.074