Group 7 of the periodic table is comprised of the elements manganese (Mn), technetium (Tc) and rhenium (Re), as well as the element of atomic number 107, and its valence are 3,4,6,7 with the systematic name of unnseptio (Uns); although this is not usually considered when referring to group 7. "Group 7" is the name recommended by IUPAC; the old European name is "VIIA group", while the old American name is "VIIB group". The name of the IUPAC should not be confused with the ancient ones, given with Roman numerals.
Manganese is a metal in the form of a block of grass very common in nature, while the other elements are very rare. Technetium has no stable isotopes and it was long believed that it was not found in nature. The rhenium is only in trace. : group of periodic table
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