Iron
Iron, (Latin ferrum,”iron”) symbol Fe, magnetic, malleable, silvery white metallic element. The atomic number of iron is 26; iron is one of the transition elements of the periodic table (see Periodic Law ). Metallic iron was known and used for ornamental purposes and weapons in prehistoric ages; the earliest specimen still extant, a group of oxidized iron beads found in Egypt, dates from about 4000 bc. The archaeological term Iron Age properly applies only to the period when iron was used extensively for utilitarian purposes, as in tools, as well as for ornamentation. The beginnings of modern processing of iron can be traced back to central Europe in the mid-14th century bc. PROPERTIES Pure iron has a hardness that ranges from 4 to 5. It is soft, malleable, and ductile. Iron is easily magnetized at ordinary temperatures; it is difficult to magnetize when heated, and at about 790° C (about 1450° F) the magnetic property disappears. Pure iron melts at about 1535° C (about 2795° F), boils...