In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings:
- The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell".
- Most scientists describe a "transition metal" as any element in the d-block of the periodic table, which includes groups 3 to 12 on the periodic table. All elements in the d-block are metals. In actual practice, the f-block is also included in the form of the lanthanide and actinide series.
Jensen has reviewed the history of the terms transition element (or metal) and d-block. The word transition was first used to describe the elements now known as the d-block by the English chemist Charles Bury in 1921, who 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 32.
Read more about Transition Metal: Classification, Characteristic Properties
Famous quotes containing the words transition and/or metal:
“When I was going through my transition of being famous, I tried to ask God why was I here? what was my purpose? Surely, it wasn’t just to win three gold medals. There has to be more to this life than that.”
—Wilma Rudolph (1940–1994)
“There were metal detectors on the staff-room doors and Hernandez usually had a drawer full of push-daggers, nunchuks, stun-guns, knucks, boot-knives, and whatever else the detectors had picked up. Like Friday morning at a South Miami high school.”
—William Gibson (b. 1948)