IODINE n.
A nonmetallic element, of the halogen group, occurring always in combination, as in the iodides. When isolated it is in the form of dark gray metallic scales, resembling plumbago, soft but brittle, and emitting a chlorinelike odor. Symbol I. Atomic weight 126.5. If heated, iodine volatilizes in beautiful violet vapors.…
IRIDIUM n.
A rare metallic element, of the same group as platinum, which it much resembles, being silver-white, but harder, and brittle, and indifferent to most corrosive agents. With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic weight 192.5.
IRON n.
The most common and most useful metallic element, being of almost universal occurrence, usually in the form of an oxide (as hematite, magnetite, etc.), or a hydrous oxide (as limonite, turgite, etc.). It is reduced on an enormous scale in three principal forms; viz., cast iron, steel, and wrought iron. Iron usually app…
ISOMERIC a.
oportions by weight, often used with with. Specif.: (a) Polymeric; i. e., having the same elements united in the same proportion by weight, but with different molecular weights; as, acetylene and benzine are isomeric (polymeric) with each other in this sense. See Polymeric. (b) Metameric; i. e., having the same element…
LANTHANUM n.
A rare element of the group of the earth metals, allied to aluminium. It occurs in certain rare minerals, as cerite, gadolinite, orthite, etc., and was so named from the difficulty of separating it from cerium, didymium, and other rare elements with which it is usually associated. Atomic weight 138.5. Symbol La. [Forme…
LEAD n.
One of the elements, a heavy, pliable, inelastic metal, having a bright, bluish color, but easily tarnished. It is both malleable and ductile, though with little tenacity, and is used for tubes, sheets, bullets, etc. Its specific gravity is 11.37. It is easily fusible, forms alloys with other metals, and is an ingredie…