Zepto-

From Wikipedia the free encyclopedia

Zepto (unit symbol z) is a unit prefix in the metric system denoting a factor of 10−21, i.e. 0.000000000000000000001.

Adopted into the International System of Units (SI) in 1991, it is derived from the Latin septem, seven, since it is equal to 1000−7.

Examples of its use:

Prefix Base 10 Decimal English word Adoption[nb 1] Etymology
Name Symbol Short scale Long scale Language Source word
yotta Y 1024 1000000000000000000000000 septillion quadrillion 1991 Latin eight[nb 2]
zetta Z 1021 1000000000000000000000 sextillion trilliard 1991 Latin seven[nb 2]
exa E 1018 1000000000000000000 quintillion trillion 1975 Greek six
peta P 1015 1000000000000000 quadrillion billiard 1975 Greek five[nb 2]
tera T 1012 1000000000000 trillion billion 1960 Greek four,[nb 2] monster
giga G 109 1000000000 billion milliard 1960 Greek giant
mega M 106 1000000 million 1873 Greek great
kilo k 103 1000 thousand 1795 Greek thousand
hecto h 102 100 hundred 1795 Greek hundred
deca da 101 10 ten 1795 Greek ten
100 1 one
deci d 10−1 0.1 tenth 1795 Latin ten
centi c 10−2 0.01 hundredth 1795 Latin hundred
milli m 10−3 0.001 thousandth 1795 Latin thousand
micro μ 10−6 0.000001 millionth 1873 Greek small
nano n 10−9 0.000000001 billionth milliardth 1960 Greek dwarf
pico p 10−12 0.000000000001 trillionth billionth 1960 Spanish peak, a little bit
femto f 10−15 0.000000000000001 quadrillionth billiardth 1964 Danish fifteen, Fermi[nb 3]
atto a 10−18 0.000000000000000001 quintillionth trillionth 1964 Danish eighteen
zepto z 10−21 0.000000000000000000001 sextillionth trilliardth 1991 Latin seven[nb 2]
yocto y 10−24 0.000000000000000000000001 septillionth quadrillionth 1991 Latin eight[nb 2]
  1. ^ Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.
  2. ^ a b c d e f Part of the beginning of the prefix was modified from the word it was derived from, ex: "peta" (prefix) vs "penta" (source word).
  3. ^ The fermi was introduced earlier with the symbol "fm", which prompted the reinterpretation of the "f" as a prefix to "m", with femto being derived from the Danish word femten due to its similarity.

References[edit]

  1. ^ "SI brochure (2019)" (PDF). SI Brochure. BIPM. p. 132. Retrieved May 23, 2019.
  2. ^ John Dell BE PhD (2009-03-25). "Mechanical engineering gone small - how to measure Zeptograms and Yoctograms using MEMS technology". University of Western Australia. Engineers Australia. Retrieved 2022-03-01.
  3. ^ "Zeptosecond birth time delay in molecular photoionization". Science. 370 (6514): 339–341. 2020-10-16. doi:10.1126/science.abb9318.
  4. ^ Temming, Maria (2021-01-29). "Physicists have clocked the shortest time span ever". Science News for Students. Retrieved 2022-03-01.