Which si prefix stands for trillionth

Similarly prefix names are also inseparable from the unit names to which they are attached. Thus, for example, millimetre, micropascal, and meganewton are single words. Compound prefix symbols, that is, prefix symbols formed by the juxtaposition of two or more prefix symbols, are not permitted. This rule also applies to compound prefix names. Prefix symbols can neither stand alone nor be attached to the number 1, the symbol for the unit one.

Prefix names and symbols are used with a number of non-SI units, but they are never used with the units of time: minute, min; hour, h; day, d. Source: Bureau International des Poids et Mesures. National variations in spelling of the prefixes are allowed by the SI. In Italian, for example, hecto- is spelled etto- and kilo- is spelled chilo-.

The symbols, however, are the same in all languages, so dam not dkm is the symbol for the dekameter and km is the symbol for the Italian chilometro. The prefixes hecto-, deka-, deci-, and centi- are widely used in everyday life but are generally avoided in scientific work. Contrary to the belief of some scientists, however, the SI does allow use of these prefixes.

The last letter of a prefix is often omitted if the first letter of the unit name is a vowel, causing the combination to be hard to pronounce otherwise. Thus ares is a hectare and 1 million ohms is a megohm. However, the last letter of the prefix is not omitted if pronunciation is not a problem, as in the case of the milliampere.

The letter "l" is sometimes added to prefixes before the erg, so 1 million ergs is a megalerg sounds odd, but better than "megerg". In computing, a custom arose of using the metric prefixes to specify powers of 2. Below, you can find the chart of 24 prefixes introduced and governed by Bureau International des Poids et Mesures eng.

International Bureau of Weights and Measures. In most English-speaking countries short scale is used. In short scale Billion prefix 10 9 is giga, Trillion prefix 10 12 is tera, Billionth prefix 10 -9 is nano, Trillionth prefix 10 is pico, and so on.