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The groups of the periodic table are numbered left to right as 1 – 18, with the f-block groups (columns) unnumbered, as recommended by IUPAC (1988). [1] Note that "group" has a chemical meaning and "column" has the tabular meaning. Alternatively, they may be named by their first element, e.g. "boron group" for group 13. [2]
When compounds contain more than one functional group, the order of precedence determines which groups are named with prefix or suffix forms. The table below shows common groups in decreasing order of precedence. The highest-precedence group takes the suffix, with all others taking the prefix form.
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.
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 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').
Hydrates are ionic compounds that have absorbed water. They are named as the ionic compound followed by a numerical prefix and -hydrate. The numerical prefixes used are listed below (see IUPAC numerical multiplier): mono-di-tri-tetra-penta-hexa-hepta-octa-nona-deca-For example, CuSO 4 ·5H 2 O is "copper(II) sulfate pentahydrate".
Compounds that contain sulfur exhibit unique chemistry due to sulfur's ability to form more bonds than oxygen, its lighter analogue on the periodic table. Substitutive nomenclature (marked as prefix in table) is preferred over functional class nomenclature (marked as suffix in table) for sulfides, disulfides, sulfoxides and sulfones.
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.