> **PROTOTYPE:** a suggestion, not an official CIAAW or IUPAC page. Official values are at [ciaaw.org](https://ciaaw.org).

# argon

| Property | Value |
| --- | --- |
| Symbol | Ar |
| Atomic number | 18 |
| IRI | `https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/Argon` |
| Wikidata | [Q696](https://www.wikidata.org/wiki/Q696) |

## Standard atomic weight

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| [39.792, 39.963] | 2017 | [10.1515/pac-2019-0603](https://doi.org/10.1515/pac-2019-0603) | Current | [`AW-Ar-standard`](../id/AW-Ar-standard.md) |
| 39.948(1) | 1979 | [10.1351/pac198052102349](https://doi.org/10.1351/pac198052102349) | Deprecated, see [`AW-Ar-standard`](../id/AW-Ar-standard.md) | [`AW-Ar-standard-1979`](../id/AW-Ar-standard-1979.md) |
| 39.948(3) | 1969 | [10.1351/pac197021010091](https://doi.org/10.1351/pac197021010091) | Deprecated, see [`AW-Ar-standard-1979`](../id/AW-Ar-standard-1979.md) | [`AW-Ar-standard-1969`](../id/AW-Ar-standard-1969.md) |
| 39.948 | 1961 | [10.1021/ja00881a001](https://doi.org/10.1021/ja00881a001) | Deprecated, see [`AW-Ar-standard-1969`](../id/AW-Ar-standard-1969.md) | [`AW-Ar-standard-1961`](../id/AW-Ar-standard-1961.md) |
| 39.944 | 1931 | [10.1039/JR9310001617](https://doi.org/10.1039/JR9310001617) | Deprecated, see [`AW-Ar-standard-1961`](../id/AW-Ar-standard-1961.md) | [`AW-Ar-standard-1931`](../id/AW-Ar-standard-1931.md) |
| 39.91 | 1925 | [10.1039/CT9252700913](https://doi.org/10.1039/CT9252700913) | Deprecated, see [`AW-Ar-standard-1931`](../id/AW-Ar-standard-1931.md) | [`AW-Ar-standard-1925`](../id/AW-Ar-standard-1925.md) |
| 39.9 | 1920 | [10.1021/ja02233a600](https://doi.org/10.1021/ja02233a600) | Deprecated, see [`AW-Ar-standard-1925`](../id/AW-Ar-standard-1925.md) | [`AW-Ar-standard-1920`](../id/AW-Ar-standard-1920.md) |
| 39.88 | 1911 | [10.1021/ja01928a001](https://doi.org/10.1021/ja01928a001) | Deprecated, see [`AW-Ar-standard-1920`](../id/AW-Ar-standard-1920.md) | [`AW-Ar-standard-1911`](../id/AW-Ar-standard-1911.md) |
| 39.9 | 1902 | [10.1007/BF01370337](https://doi.org/10.1007/BF01370337) | Deprecated, see [`AW-Ar-standard-1911`](../id/AW-Ar-standard-1911.md) | [`AW-Ar-standard-1902`](../id/AW-Ar-standard-1902.md) |


## Isotopes

| A | Representative isotopic composition | Year | Source | Declaration | ChEBI | Wikidata |
| --- | --- | --- | --- | --- | --- | --- |
| [36](../id/Ar-36.md) | [0.0000, 0.0207] | — | — | [`Abundance-Ar36`](../id/Abundance-Ar36.md) | — | [Q2019992](https://www.wikidata.org/wiki/Q2019992) |
| [38](../id/Ar-38.md) | [0.000, 0.043] | — | — | [`Abundance-Ar38`](../id/Abundance-Ar38.md) | — | [Q2801372](https://www.wikidata.org/wiki/Q2801372) |
| [40](../id/Ar-40.md) | [0.936, 1.000] | — | — | [`Abundance-Ar40`](../id/Abundance-Ar40.md) | — | [Q1929004](https://www.wikidata.org/wiki/Q1929004) |

Notes: [g](#note-g) [r](#note-r)

## Notes

<a id="note-g"></a>**g** Geological and biological materials are known in which the element has an isotopic composition outside the limits for normal material. The difference between the atomic weight of the element in such materials and that given in the table may exceed the stated uncertainty.

<a id="note-r"></a>**r** Range in isotopic composition of normal terrestrial material prevents a more precise standard atomic weight being given; the tabulated value and uncertainty should be applicable to normal material.

## Bibliography

<div class="csl-bib-body">
<div class="csl-entry">Aston, F. W., Baxter, G. P., Brauner, B., Debierne, A., Leduc, A., Richards, T. W., Soddy, F., &#38; Urbain, G. (1925). Second Report of the International Committee of the International Union of Pure and Applied Chemistry on the chemical elements. International atomic weights, 1925. <i>Journal of the Chemical Society, Transactions</i>, <i>127</i>, 913. https://doi.org/10.1039/ct9252700913 <a href="https://doi.org/10.1039/CT9252700913">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1039/CT9252700913">Scholia</a></div>
<div class="csl-entry">Atomic weights of the elements 1969. (1970). <i>Pure and Applied Chemistry</i>, <i>21</i>(1), 91–108. https://doi.org/10.1351/pac197021010091 <a href="https://doi.org/10.1351/pac197021010091">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac197021010091">Scholia</a></div>
<div class="csl-entry">Atomic Weights of the Elements 1979. (1980). <i>Pure and Applied Chemistry</i>, <i>52</i>(10), 2349–2384. https://doi.org/10.1351/pac198052102349 <a href="https://doi.org/10.1351/pac198052102349">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac198052102349">Scholia</a></div>
<div class="csl-entry">Baxter, G. P., Curie, Mme. M., Hönigschmid, O., Lebeau, P., &#38; Meyer, R. J. (1931). First Report of the Committee on the Atomic Weights of the International Union of Chemistry. <i>J. Chem. Soc.</i>, <i>0</i>(0), 1617–1627. https://doi.org/10.1039/jr9310001617 <a href="https://doi.org/10.1039/JR9310001617">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1039/JR9310001617">Scholia</a></div>
<div class="csl-entry">Cameron, A. E., &#38; Wichers, Edward. (1962). <b>Report of the International Commission on Atomic Weights<sup>*</sup>(1961)</b>. <i>Journal of the American Chemical Society</i>, <i>84</i>(22), 4175–4197. https://doi.org/10.1021/ja00881a001 <a href="https://doi.org/10.1021/ja00881a001">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja00881a001">Scholia</a></div>
<div class="csl-entry">Clarke, F. W., Thorpe, T. E., Ostwald, W., &#38; Urbain, G. (1910). ANNUAL REPORT OF THE INTERNATIONAL COMMITTEE ON ATOMIC WEIGHTS, 1911. <i>Journal of the American Chemical Society</i>, <i>32</i>(10), 1113–1116. https://doi.org/10.1021/ja01928a001 <a href="https://doi.org/10.1021/ja01928a001">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja01928a001">Scholia</a></div>
<div class="csl-entry">Clarke, F., Thorpe, T., &#38; Urbain, G. (1919). Report of the International Committee on Atomic Weights for 1919-1920. <i>Journal of the American Chemical Society</i>, <i>41</i>(12), 1881–1887. https://doi.org/10.1021/ja02233a600 <a href="https://doi.org/10.1021/ja02233a600">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja02233a600">Scholia</a></div>
<div class="csl-entry">Prohaska, T., Irrgeher, J., Benefield, J., Böhlke, J. K., Chesson, L. A., Coplen, T. B., Ding, T., Dunn, P. J. H., Gröning, M., Holden, N. E., Meijer, H. A. J., Moossen, H., Possolo, A., Takahashi, Y., Vogl, J., Walczyk, T., Wang, J., Wieser, M. E., Yoneda, S., … Meija, J. (2022). Standard atomic weights of the elements 2021 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>94</i>(5), 573–600. https://doi.org/10.1515/pac-2019-0603 <a href="https://doi.org/10.1515/pac-2019-0603">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1515/pac-2019-0603">Scholia</a></div>
<div class="csl-entry">Richards, Baxter, Hinrichsen, Köthner, P., &#38; Pellini, S. (1902). Zur Festsetzung der Atomgewichte. <i>Fresenius’ Zeitschrift für analytische Chemie</i>, <i>41</i>(2), 139–140. https://doi.org/10.1007/bf01370337 <a href="https://doi.org/10.1007/BF01370337">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1007/BF01370337">Scholia</a></div>
</div>

## Turtle

This resource as a file: [Argon.ttl](Argon.ttl)

```turtle
# Prototype: a suggestion, not an official CIAAW or IUPAC record. Official values are at https://ciaaw.org

@prefix adms: <http://www.w3.org/ns/adms#> .
@prefix chemrof: <https://w3id.org/chemrof/> .
@prefix ciaaw: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/ciaaw-draft#> .
@prefix ciaaw_draft: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/id/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix element: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix unit: <http://qudt.org/vocab/unit/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ciaaw_draft:AW-Ar-standard-1902 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1911 ;
    dcterms:issued "1902"^^xsd:gYear ;
    dcterms:source <https://doi.org/10.1007/BF01370337> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.9 ] .

ciaaw_draft:AW-Ar-standard a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:issued "2017"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1979 ;
    dcterms:source <https://doi.org/10.1515/pac-2019-0603> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:lowerBound 39.792 ;
            qudt:upperBound 39.963 ;
            ciaaw:significantFiguresLower 5 ;
            ciaaw:significantFiguresUpper 5 ] .

ciaaw_draft:AW-Ar-standard-1911 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1920 ;
    dcterms:issued "1911"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1902 ;
    dcterms:source <https://doi.org/10.1021/ja01928a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.88 ] .

ciaaw_draft:AW-Ar-standard-1920 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1925 ;
    dcterms:issued "1920"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1911 ;
    dcterms:source <https://doi.org/10.1021/ja02233a600> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.9 ] .

ciaaw_draft:AW-Ar-standard-1925 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1931 ;
    dcterms:issued "1925"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1920 ;
    dcterms:source <https://doi.org/10.1039/CT9252700913> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.91 ] .

ciaaw_draft:AW-Ar-standard-1931 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1961 ;
    dcterms:issued "1931"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1925 ;
    dcterms:source <https://doi.org/10.1039/JR9310001617> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.944 ] .

ciaaw_draft:AW-Ar-standard-1961 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1969 ;
    dcterms:issued "1961"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1931 ;
    dcterms:source <https://doi.org/10.1021/ja00881a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.948 ] .

ciaaw_draft:AW-Ar-standard-1969 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard-1979 ;
    dcterms:issued "1969"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1961 ;
    dcterms:source <https://doi.org/10.1351/pac197021010091> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.948 ;
            qudt:standardUncertainty 0.003 ;
            ciaaw:significantFigures 5 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Ar-standard-1979 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Ar-standard ;
    dcterms:issued "1979"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Ar-standard-1969 ;
    dcterms:source <https://doi.org/10.1351/pac198052102349> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Argon ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 39.948 ;
            qudt:standardUncertainty 0.001 ;
            ciaaw:significantFigures 5 ;
            ciaaw:significantFiguresUncertainty 1 ] .

element:Argon a chemrof:ChemicalElement ;
    rdfs:label "argon"@en ;
    ciaaw:currentStandardAtomicWeight ciaaw_draft:AW-Ar-standard ;
    ciaaw:hasDeclaration ciaaw_draft:AW-Ar-standard,
        ciaaw_draft:AW-Ar-standard-1902,
        ciaaw_draft:AW-Ar-standard-1911,
        ciaaw_draft:AW-Ar-standard-1920,
        ciaaw_draft:AW-Ar-standard-1925,
        ciaaw_draft:AW-Ar-standard-1931,
        ciaaw_draft:AW-Ar-standard-1961,
        ciaaw_draft:AW-Ar-standard-1969,
        ciaaw_draft:AW-Ar-standard-1979 ;
    ciaaw:hasIsotope ciaaw_draft:Ar-36,
        ciaaw_draft:Ar-38,
        ciaaw_draft:Ar-40 ;
    ciaaw:standardAtomicWeightLower 39.792 ;
    ciaaw:standardAtomicWeightUpper 39.963 ;
    chemrof:atomic_number 18 ;
    chemrof:symbol "Ar" .
```

[All atomic weights](../atomic-weights.md) · [All isotopic abundances](../isotopic-abundances.md)