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The numerals for 4 (IV) ... In chemistry, Roman numerals are sometimes used to denote the groups of the periodic ... stylised Roman numerals may represent numeric values.
Compounds with a positive ion : The name of the compound is simply the cation's name (usually the same as the element's), followed by the anion. For example, NaCl is sodium chloride, and CaF 2 is calcium fluoride. Cations of transition metals able to take multiple charges are labeled with Roman numerals in parentheses to indicate their charge.
The numbers 200-900 would be confused easily with 22 to 29 if they were used in chemistry. khīlioi = 1000, diskhīlioi = 2000, triskhīlioi = 3000, etc. 13 to 19 are formed by starting with the Greek word for the number of ones, followed by και (the Greek word for 'and'), followed by δέκα (the Greek word for 'ten').
In the field of semiconductor physics, it is still universally called group IV. The group is also known as the tetrels (from the Greek word tetra , which means four), stemming from the Roman numeral IV in the group name, or (not coincidentally) from the fact that these elements have four valence electrons (see below).
Stock nomenclature for inorganic compounds is a widely used system of chemical nomenclature developed by the German chemist Alfred Stock and first published in 1919. In the "Stock system", the oxidation states of some or all of the elements in a compound are indicated in parentheses by Roman numerals. [1] [2]
IUPAC nomenclature is used for the naming of chemical compounds, based on their chemical composition and their structure. [1] For example, one can deduce that 1-chloropropane has a Chlorine atom on the first carbon in the 3-carbon propane chain.
The main purpose of chemical nomenclature is to disambiguate the spoken or written names of chemical compounds: each name should refer to one compound. Secondarily, each compound should have only one name, although in some cases some alternative names are accepted. Preferably, the name should also represent the structure or chemistry of a compound.
In the United States, the Roman numerals were followed by either an "A" if the group was in the s-or p-block, or a "B" if the group was in the d-block. The Roman numerals used correspond to the last digit of today's naming convention (e.g. the group 4 elements were group IVB, and the group 14 elements were group IVA).