Cadmium is an element of group 12 and of period 5. Stricto sensu,
it is a poor metal, which does not meet the definition of transition elements by
IUPAC [8]; in practice, however, it is very often assimilated to transition
metals in textbooks and numerous works. It is part of the ˇ°zinc groupˇ±, or group
IIB, which includes, by increasing atomic number, 30Zn, 48Cd and 80Hg, elements
characterized by two electrons on the s sublayer beyond a complete d sublayer .
The electronic configuration of cadmium is [Kr] 4d10 5s2. Zinc and cadmium are
fairly similar electropositive metals.
Yellowish Smithsonite containing cadmium
The word cadmium comes from the medieval Latin cadmia or from the Greco-Latin
kadmeia, old name given to zinc carbonate, before the definitive name of
smithsonite, allotted in 1832 by François Sulpice Beudant. Miners around the
ancient city of Thebes were already extracting this ore to make various
"brasses" and "bronzes". Recall that the Theban city in Boeotia is founded
according to legend by the foreign warrior Cadmos or Cadmus, whose citadel and
kingdom thus bear the name of Kadmeia, in French Cadm¨¦e.
This name is therefore related by its root to that of the mixture called
"calamine", but also of the mineral defined calamine. The Greco-Latin term
cadmia designated in Europe at the same time all the types of ores of oxidized
zinc, that are the calamines described in a learned way, and in the technical
tradition, the cadmia fornacum or cadmies, these deposits of dust and oxides of
metal, formed on the walls of metallurgical furnaces [10]. For example, in the
Larousse dictionary of the XXth century published after 1920, the caddy
designates in the first place the residue which attaches to the wall of the
blast furnace chutes, and in another denomination qualified by the adverb
formerly, corresponds to the calamine, in the sense of defined mineral and / or
mineral rock, that is to say in relation to the body "cadmium carbonate" which
in its pure state, is called smithsonite. The adjective "cadmic" mentions what
relates to cadmium (element or simple body), or qualifies what contains cadmium.
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