Group 7 of the Periodic Table

Group 7 (also called Group VII) is the seventh column of the periodic table of chemical elements. It comprises manganese (Mn), technetium (Tc), rhenium (Re), and bohrium (Bh). All are transition metals, meaning their electrons occupy an incompletely filled d-shell.

The elements in this group typically have an electron configuration (n−1)d⁵ ns², yielding seven valence electrons. For this reason they can reach an oxidation state of +7, the highest possible. Lower oxidation states such as +2, +4, and +6 are also common, particularly in manganese.

Manganese

Manganese, atomic number 25, is the only element in this group to occur abundantly in rocks and minerals of the Earth's crust. It is extracted chiefly from the ore pyrolusite (manganese dioxide). Its largest use is in the steel and alloy industries, where it is used to harden steel. Manganese is also a trace nutrient required by living organisms and is part of the enzymes involved in plant photosynthesis.

Technetium

Technetium, atomic number 43, was the first element to be artificially synthesized; its name derives from the Greek word for 'artificial'. Every isotope of technetium is radioactive, and therefore it occurs naturally in extremely small amounts on Earth. The isotope technetium-99m is widely used in nuclear medical imaging.

Rhenium

Rhenium, atomic number 75, is among the rarest elements in the Earth's crust and is found mainly in molybdenum ores. It has the highest melting point of the lighter elements in this group. It is used in superalloys for aircraft engines and also in petroleum refining catalysts.

Bohrium

Bohrium, atomic number 107, is a synthetic superheavy element named after physicist Niels Bohr. It is produced in particle accelerators by colliding heavy ions; the resulting atoms are extremely rare and short-lived. Consequently its chemical properties are estimated through minimal experiments and computational prediction.