A sesquioxide is an
oxide
An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...
of an
element (or
radical
Radical may refer to:
Politics and ideology Politics
*Radical politics, the political intent of fundamental societal change
*Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and ...
), where the ratio between the number of
atoms
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons.
Every solid, liquid, gas, an ...
of that element and the number of atoms of
oxygen is 2:3. For example,
aluminium oxide and
phosphorus(III) oxide are sesquioxides.
Many sesquioxides contain a
metal in the +3
oxidation state and the oxide ion , e.g.,
aluminium oxide ,
lanthanum(III) oxide and
iron(III) oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally ...
. Sesquioxides of
iron and
aluminium are found in
soil. The
alkali metal
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...
sesquioxides are exceptions because they contain both
peroxide and
superoxide ions, e.g.,
rubidium sesquioxide is formulated . Sesquioxides of
metalloids and
nonmetals are exceptions too, e.g.
boron trioxide ,
dinitrogen trioxide and phosphorus(III) oxide .
Many
transition metal oxides crystallize in the
corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the pres ...
structure type, with
space group Rc. Sesquioxides of
rare earth elements crystalize into one or more of three crystal structures: hexagonal (type A, space group Pm1), monoclinic (type B, space group C2/m), or body-centered cubic (type C, space group Ia).
Sesquioxidizing, meaning the creation of a sesquioxide, is the highest scoring word that would fit on a
Scrabble board, though it does not actually appear in any official Scrabble dictionary. Though the
Oxford English Dictionary already listed the noun and the past participle adjective — sesquioxidation and sesquioxidized, respectively — the verb, sesquioxidize, and its conjugated forms, have been absent from the dictionaries used as sources for the official Scrabble word lists. An early appearance of the noted present participle had occurred in the 1860 publication of the State of New York's Legislative Assembly's Transactions of the State Medical Society, yet the word's first appearance in a dictionary was in the 1976 edition of Josepha Heifetz Byrne's ''Mrs. Byrne's Dictionary of Unusual, Obscure, and Preposterous Words'' (), One could theoretically score 2044 points in a single move, when otherwise only words from the
official Scrabble word list are used.
Record for the Highest Scoring Scrabble Move
at scrabulizer.com, accessed 2008-05-30
List of sesquioxides
References
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