Definition, Meaning & Synonyms

atto

prefix

ˈæt.oʊ

Definition

A metric prefix used in the International System of Units (SI) that represents a factor of 10^-18.

Examples

The mass of a single proton is about 1.67 attograms.
In quantum physics, the behavior of particles can be observed in the attosecond regime.
The energy levels of certain atoms can be measured in atto electron volts.

Meaning

The term ‘atto’ denotes one quintillionth of a unit, symbolized as ‘a’. It is commonly used in scientific measurements to convey extremely small quantities.