Manganese Group: Elements of the Seventh Subgroup

This chapter describes the chemical and physical properties, occurrence, manufacturing processes, applications, and patents of the elements of the seventh subgroup of the periodic table of elements with their most important compounds. Pure manganese has only a few technical applications, but very large quantities are alloyed with steel to form ferromanganese, which is significantly harder and more corrosion-resistant than steel. Manganese-IV-oxide is used extensively in alkali-manganese batteries. Technetium is produced in nuclear reactors in quantities of a few t/a by fission of the uranium isotope 23592U. The majority of the technetium obtained is used as a radiotherapeutic. Its most important isotope is 99m43Tc, whose short half-life, soft γ-radiation, and the ability to attach to molecules present in the human body, make it an ideal tracer for scintigraphy. Ammonium or potassium pertechnetate are effective rust inhibitors for steel. Rhenium is often found in alloys with nickel, which are resistant to fatigue fractures. It is also contained in catalysts. Bohrium does not occur naturally; all its isotopes are radioactive and must be made artificially. During the official first production of the element in 1981, five atoms of the isotope 262107Bh were obtained.