View source for Yocto-

'''''Yocto''''' (symbol '''y''') is a [[Metric prefix|unit prefix]] in the [[Metric system|metric system]] denoting a factor of 10<sup>−24</sup> or {{gaps|0.000|000|000|000|000|000|000|001}}.

It was adopted in 1991<ref>{{cite web
| url=https://www.bipm.org/documents/20126/33145745/CGPM19.pdf/3f65ecf1-f86e-b86c-5c28-709d9f12eec4
| title=Resolution 4 of the 19th CGPM
| date=1991
| publisher=BIPM
| work=Conférence générale des poids et mesures
| format=PDF
| access-date=2020-05-14}}</ref> by the [[General Conference on Weights and Measures]]. It comes from the [[Social:Latin|Latin]] ''octo''<ref>[https://www.bipm.org/en/committees/cg/cgpm/19-1991 Proceedings of the 19th CGPM (1991)], page 80. Retrieved 2022-02-16</ref> or the [[Social:Ancient Greek|Ancient Greek]] {{lang|grc|οκτώ}}, meaning "eight", because it is equal to 1000<sup>−8</sup>. ''Yocto-'' is the smallest official [[SI prefix]].

It can be used to state a [[Physics:Subatomic particle|subatomic particle]]'s [[Physics:Mass|mass]], for example: 
::{|
|-
| [[Physics:Electron mass|Electron mass]]:        || {{val|0.000911|u=yg}}
|-
| [[Physics:Proton|Proton]] mass:          || {{val|1.6726|u=yg}}
|-
| [[Physics:Neutron|Neutron]] mass:         || {{val|1.6749|u=yg}}
|-
| [[Physics:Atomic mass constant|Atomic mass constant]]: || {{val|1.6605|u=yg}}
|-
|}

{{SI prefixes (infobox)}}

==References==
{{Reflist}}

[[Category:SI prefixes]]

{{Sourceattribution|Yocto-|1}}