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:
“Some of the taverns on this road, which were particularly dirty, were plainly in a transition state from the camp to the house.”
—Henry David Thoreau (1817–1862)
“And, indeed, is there not something holy about a great kitchen?... The scoured gleam of row upon row of metal vessels dangling from hooks or reposing on their shelves till needed with the air of so many chalices waiting for the celebration of the sacrament of food. And the range like an altar, yes, before which my mother bowed in perpetual homage, a fringe of sweat upon her upper lip and the fire glowing in her cheeks.”
—Angela Carter (1940–1992)