Nomenclature
CAS number: 7440-74-6
Description and references
In; at. wt 114.818; at. no. 49; valence 3,
2, 1. Group IIIA(13). Natural isotopes: 115 (95.77%); 113 (4.23%); 115In is a β emitter, T 6 × 1014 years. Artificial radioactive isotopes: 107-112; 114;
116-124. Occurrence in the earth's crust: 1 × 105%.
Discovered in sphalerite ore by Reich and Richter in 1863. Generally
found in zinc blendes. Monograph: M. T. Ludwick, Indium (Indium Corp. of America, Utica, N.Y.,
1950). Review: Wade, Banister in Comprehensive Inorganic Chemistry vol. 1, J.
C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973)
pp 997-1000, 1065-1117; E. F. Milner, C. E. T. White in Kirk-Othmer Encyclopedia of Chemical Technology vol. 13 (Wiley-Interscience, New York, 3rd ed., 1981)
pp 207-212.
Properties
Soft, white metal with bluish tinge. Emits a “tin
cry” on bending. Ductile, malleable, softer than lead, leaves a mark
on paper. Quite stable in air. Crystallizes and is diamagnetic.
d20 7.3.
mp 155°. bp 2000°. Sp heat:
0.0568 cal/g/°C. Hardness (Mohs') = 1.2. Unaffected by water; attacked
by mineral acids. Very resistant to alkalies.Caution
Indium salts are relatively nontoxic
when administered orally; highly toxic when administered subcutaneously
or intravenously. Experimental animal poisoning has produced injury
to blood, heart, liver, kidneys: E. Browning, Toxicity of Industrial Metals (Appleton-Century-Crofts,
New York, 2nd ed., 1969) pp 164-168.Use
In bearing alloys; as a thin film on moving surfaces
made from other metals. In dental alloys. In semiconductor research.
In nuclear reactor control rods (in the form of an Ag-In-Cd alloy).