from
The Collaborative International Dictionary of English v.0.48
Gallium \Gal"li*um\, n. [NL.; perh. fr. L. Gallia France.]
(Chem.)
A rare metallic element, found combined in certain zinc ores.
It is white, hard, and malleable, resembling aluminium, and
remarkable for its low melting point (86[deg] F., 30[deg]
C.). Symbol, Ga; at. wt., 69.9. Gallium is chiefly trivalent,
resembling aluminium and indium. It was predicted with most
of its properties, under the name eka-aluminium, by the
Russian chemist Mendelyeev on the basis of the periodic law.
This prediction was verified in its discovery (in 1875) by
the French chemist Lecoq de Boisbaudran by its characteristic
spectrum (two violet lines), in an examination of a zinc
blende from the Pyrenees.
[Webster 1913 Suppl.]
from
The Elements (07Nov00)
gallium
Symbol: Ga
Atomic number: 31
Atomic weight: 69.72
Soft silvery metallic element, belongs to group 13 of the periodic
table.
The two stable isotopes are Ga-69 and Ga-71. Eight radioactive isotopes
are known, all having short half-lives. Gallium Arsenide is used as a
semiconductor. Corrodes most other metals by diffusing into their
lattice.
First identified by Francois Lecoq de Boisbaudran in 1875.