Period 6 element living organism. Tungsten interferes with molybdenum and copper metabolism, and is somewhat toxic to animal life. Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an "estimated" average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. The free element has the third-highest melting point and highest boiling point of any element. Rhenium resembles manganese chemically and is obtained as a by-product of molybdenum and copper ore's extraction and refinement. Rhenium
Transition metal prevent d–d bonding, which again tends to differentiate them from the accepted transition metals. Mercury has a melting point of and is a liquid at room temperature. Transition metal In chemistry, the term transition metal (or transition element) has three possible meanings: English chemist Charles Bury (1890–1968) first used the word "transition" in this context in 1921, when he referred to a "transition series of elements" during the change of an inner layer of electrons (for example n=3 in the 4th row of the periodic table) from a stable group of 8 to one of 18, or from 18 to