Prefix

It is never wrong to use only the fundamental units. In many situations that just means the numbers are either very large or very small. To keep numbers to reasonable sizes, scientists use units derived from the fundamental set of units using metric prefixes. These prefixes and their abbreviations are the following  

The symbol p is the Greek letter mu and is used because m was already in use. The letter m can be the abbreviation for either meter or milli. It is usually clear from the context which meaning is intended. 

The origin of the prefix femto is the Danish word femten, meaning fifteen . Pico is derived from the Italian word piccolo, meaning small. Nano is derived from the Greek word vavoq, meaning dwarf.  

The wide range in magnitude of units used in normal practice requires the use of different-sized units, rather than a powers-of-ten numerical multiplier. Accordingly, SI has 

Note the first syllable of every prefix is accented so as to retain its identity, that is kill oh meter. When written out the prefix is not capitalized even though its symbol may be a capital letter. 

1 inch = 2.5400 centimeters 1 foot = 0.3048 meter 1 yard = 0.9144 meter 1 mile = 1.6093 kilometers 

1 centimeter = 0.3937 inch 1 meter = 3.281 feet 1 meter = 1.0936 yards 1 kilometer = 0.62137 miles 

1 fluid ounce = 29.5730 milliliters 1 liquid pint = 0.4732 liter 1 liquid quart = 0.9463 liter 1 gallon = 3.7853 liters 1 dry quart = 1.1012 liters 

1 milliliter = 0.0338 fluid ounce 1 liter = 2.1134 fluid pints 1 liter = 1.0567 liquid quarts 1 liter = 0.2642 gallon 1 liter = 0.908 1 dry quart 

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The same nomenclature has been adopted for amino-acids, the configurational family to which the a-carbon atom belongs being denoted by the prefixes d- and L-. 

The prefix is also used in orthophosphates, orthocarbonates, orthoformates and ortho-silicates, which are derivatives of POCOH), the hypothetical C(OH)4, HC(OH)3 and Si(OH)4 respectively in these the word ortho is always written in full. 

OH groups are in the para or 1,4 position to each other. This use of the prefix is confined to disubstituted benzene derivatives in such cases as para-hydrogen and paraldehyde the prefix has no uniform structural significance and is always written in full. 

Either by alkyl groups which are designated by the letter R, which is equivalent to to give alkyl-aromatics. The prefixes ortho, meta... 

The most common prefixes are written below using the alkane series as an example, and the prefixes are highlighted ... 

The Wood notation ean be generalized somewhat fiirther, by adding either the prefix e for eentred, or the prefix p for primitive. For instanee, one may have a e (2 x 2) unit eell or a p(2 x 2) unit eell, the latter often abbreviated to (2 x 2) beeause it is identieal to it. In a eentred unit eell, the eentre of the eell is an exaet eopy of the eomers of the eell this makes the eell non-primitive, i.e. it is no longer the smallest eell that, when repeated periodieally aeross the surfaee, generates the entire surfaee stnieture. Nonetheless, the eentred notation is often used beeause it ean be quite eonvenient, as the next example will illustrate. 

It has become fashionable to prefix the names of disciplines with bio , as in biophysics, bioinfonnatics and so on, giving the impression that in order to deal with biological systems, a different kind of physics, or infonnation science, is needed. But there is no imperative for this necessity. Biological systems are often very complex and compartmentalized, and their scaling laws may be different from those familiar in inanimate systems, but this merely means that different emphases from those useful in dealing with large unifonn systems are required, not that a separate branch of knowledge should necessarily be developed. 

For larger systems, various approximate schemes have been developed, called mixed methods as they treat parts of the system using different levels of theory. Of interest to us here are quantuin-seiniclassical methods, which use full quantum mechanics to treat the electrons, but use approximations based on trajectories in a classical phase space to describe the nuclear motion. The prefix quantum may be dropped, and we will talk of seiniclassical methods. There are a number of different approaches, but here we shall concentrate on the few that are suitable for direct dynamics molecular simulations. An overview of other methods is given in the introduction of [21]. 

The small capital letter prefix refers to configuration, related to n glyceraldehyde, and not to the direction of optical rotation. The sign of optical rotation is expressed as (+) and (—) or as d and I or by the words dextro and Uuvo. Th is we have n.( —)-fructose and ,-(+).arabinose. 

The name found its origin in the fact that the first dyes known were all derived from quinoline as, for example, 2,2 -cyanine (Scheme 1). In the case of an asymmetrical or symmetrical dye involving one or two nuclei that are different from the quinoline ring, the name of the nucleus becomes the prefix in the name of the dye. So 3.3 -dimethyl-4-phenyl thiazolo cyanine is the dye of structure 1 and 3.1 -dimethyl 4-phenyl thiazolo 2 -cyanine is represented by the formula structure 2 (Scheme 2). 

The suffix /Tier in the word isomer is derived from the Greek word meros meaning part share or por tion The prefix /so is also from Greek (isos meaning the same ) Thus isomers are different molecules that have the same parts (ele mental composition)... 

The lUPAC rules assign names to unbranched alkanes as shown m Table 2 2 Methane ethane propane and butane are retained for CH4 CH3CH3 CH3CH2CH3 and CH3CH2CH2CH3 respectively Thereafter the number of carbon atoms m the chain is specified by a Latin or Greek prefix preceding the suffix ane which identifies the com pound as a member of the alkane family Notice that the prefix n is not part of the lUPAC system The lUPAC name for CH3CH2CH2CH3 is butane not n butane... 

Both remaining CgHi4 isomers have two methyl groups as substituents on a four carbon chain Thus the parent chain is butane When the same substituent appears more than once use the multiplying prefixes di tri tetra and so on A separate locant is used for each substituent and the locants are separated from each other by commas and from the words by hyphens... 

Replicating prefixes such as di tri and tetra (see Section 2 12) are used as... 

Italicized prefixes such as sec and tert are ignored when alphabetizing except when they are compared with each other tert Butyl precedes isobutyl and sec butyl precedes tert butyl... 

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