from
The Collaborative International Dictionary of English v.0.48
Indium \In"di*um\, n. [NL. See {Indigo}.] (Chem.)
A rare metallic element, of atomic number 49, discovered in
certain ores of zinc, by means of its characteristic spectrum
of two indigo blue lines; hence, its name. In appearance it
resembles zinc, being white or lead gray, soft, malleable and
easily fusible, but in its chemical relation it resembles
aluminium or gallium (valence +3). Symbol In. Atomic weight,
114.82.
[1913 Webster +PJC]
from
The Elements (07Nov00)
indium
Symbol: In
Atomic number: 49
Atomic weight: 114.82
Soft silvery element belonging to group 13 of the periodic table. The
most
common natural isotope is In-115, which has a half-life of 6*10^4 years.
Five other radioisotopes exist. Discovered in 1863 by Reich and Richter.