Manganese group. Elements of the seventh subgroup. A journey through the periodic table

The author presents in detail the elements of the seventh subgroup (manganese group). He shows that the elements of this group, with the exception of manganese, are chemically usually relatively inert and show regular gradations of their properties. Thus, from manganese to rhenium density, melting and boiling points increase, but the reactivity decreases. Manganese is found as a constituent of very hard steels, technetium is used as a radiotherapeutic agent, manganese dioxide is needed in electric batteries, potassium permanganate as a disinfectant and rhenium as a component of fatigue-free alloys for turbine blades. Technetium was the first element that could only be synthesized for the first time. Rhenium is one of the rarest elements in the Earth's shell and only manganese is still relatively abundant at 850 ppm. Bohrium, the heaviest element in the group, is also only accessible through artificial processes (nuclear fusion).