53 / 125

10-31

half life

URNurn:iso:std:iso:80000:-10:ed-2:en:item:10-31

https://metanorma.github.io/isq-smart/quantities/part-10/t10-31
urn:iso:std:iso:80000:-10:ed-2:en:item:10-31

ISQ Identifiers

ISO

urn:iso:std:iso:80000:-10:ed-2:en:item:10-31

IEC

urn:iec:std:iec:80000-10:2019:::item:10-31

Designations

ENhalf life

FRpériode radioactive

Symbol

T_{1 / 2}

Notation systems

Rendered

T_{1 / 2}

AsciiMath

T_(1//2)

LaTeX

T_{1 / 2}

Definition

mean duration (ISO 80000-3: Space and time) required for the decay of one half of the atoms or nuclei

durée (ISO 80000-3: Space and time) moyenne nécessaire pour la désintégration de la moitié des atomes ou des noyaux

Units

s

second

View related quantities →

Notes

For exponential decay, $T_{1 / 2} = (ln 2) / λ$ , where $λ$ is the decay constant (decay constant).

Pour une décroissance exponentielle, $T_{1 / 2} = (ln 2) / λ$ , où $λ$ est la constante de désintégration (decay constant).

Concept HierarchyPendrill (2024)

Ttime-type quantitiesLevel 0 · Kind

Broader concepts

◇ time-type quantities

Characterizes

● atom

Ontology
isq:Quantity smart:TermEntry

Class Hierarchy

smart:Entity smart:TermEntryisq:Quantity

A physical quantity as defined in ISO/IEC 80000, with associated symbols, definitions, and units of measurement.

Instance IRI

isq:t10-31

Properties

isq:QuantityShape

Property	Value
rdf:type	isq:Quantity smart:TermEntry
dcterms:identifier	10-31
skosxl:prefLabel	"half life"@en
skosxl:altLabel	"T_(1//2)"@en
skos:definition	mean duration (<<iso80000-3>>) required for the decay of one half of the atoms or nuclei
skos:note	For exponential decay, stem:[T_(1//2) = ("ln"2)//lambda], where stem:[lambda] is the decay constant (<<t10-24>>).
isq:hasUnit	s (second)
isq:hasDimension	isq:Dimension
smart:hasBindingnessType	bindingness-type:normative
dcterms:isPartOf	isq:part-10

Related Entities

isq:QuantityShape isq:part-10 isq:Unit isq:Dimension isq:hasDimension smart:TermEntry