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

# chlorine

| Property | Value |
| --- | --- |
| Symbol | Cl |
| Atomic number | 17 |
| IRI | `https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/Chlorine` |
| Wikidata | [Q688](https://www.wikidata.org/wiki/Q688) |

## Standard atomic weight

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| [35.446, 35.457] | 2009 | [10.1351/PAC-REP-10-09-14](https://doi.org/10.1351/PAC-REP-10-09-14) | Current | [`AW-Cl-standard`](../id/AW-Cl-standard.md) |
| 35.453(2) | 1999 | [10.1351/pac200173040667](https://doi.org/10.1351/pac200173040667) | Deprecated, see [`AW-Cl-standard`](../id/AW-Cl-standard.md) | [`AW-Cl-standard-1999`](../id/AW-Cl-standard-1999.md) |
| 35.4527(9) | 1985 | [10.1351/pac198658121677](https://doi.org/10.1351/pac198658121677) | Deprecated, see [`AW-Cl-standard-1999`](../id/AW-Cl-standard-1999.md) | [`AW-Cl-standard-1985`](../id/AW-Cl-standard-1985.md) |
| 35.453(1) | 1961 | [10.1021/ja00881a001](https://doi.org/10.1021/ja00881a001) | Deprecated, see [`AW-Cl-standard-1985`](../id/AW-Cl-standard-1985.md) | [`AW-Cl-standard-1961`](../id/AW-Cl-standard-1961.md) |
| 35.457 | 1925 | [10.1039/CT9252700913](https://doi.org/10.1039/CT9252700913) | Deprecated, see [`AW-Cl-standard-1961`](../id/AW-Cl-standard-1961.md) | [`AW-Cl-standard-1925`](../id/AW-Cl-standard-1925.md) |
| 35.46 | 1909 | [10.1021/ja01931a001](https://doi.org/10.1021/ja01931a001) | Deprecated, see [`AW-Cl-standard-1925`](../id/AW-Cl-standard-1925.md) | [`AW-Cl-standard-1909`](../id/AW-Cl-standard-1909.md) |
| 35.45 | 1902 | [10.1007/BF01370337](https://doi.org/10.1007/BF01370337) | Deprecated, see [`AW-Cl-standard-1909`](../id/AW-Cl-standard-1909.md) | [`AW-Cl-standard-1902`](../id/AW-Cl-standard-1902.md) |

Notes: [m](#note-m)

## Isotopes

| A | Representative isotopic composition | Year | Source | Declaration | ChEBI | Wikidata |
| --- | --- | --- | --- | --- | --- | --- |
| [35](../id/Cl-35.md) | [0.755, 0.761] | — | — | [`Abundance-Cl35`](../id/Abundance-Cl35.md) | — | [Q2783861](https://www.wikidata.org/wiki/Q2783861) |
| [37](../id/Cl-37.md) | [0.239, 0.245] | — | — | [`Abundance-Cl37`](../id/Abundance-Cl37.md) | — | [Q5102949](https://www.wikidata.org/wiki/Q5102949) |

Notes: [m](#note-m)

## Notes

<a id="note-m"></a>**m** Modified isotopic compositions may be found in commercially available material because the material has been subjected to some undisclosed or inadvertent isotopic fractionation. Substantial deviations in atomic weight of the element from that given in the table can occur.

## 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 1985. (1986). <i>Pure and Applied Chemistry</i>, <i>58</i>(12), 1677–1692. https://doi.org/10.1351/pac198658121677 <a href="https://doi.org/10.1351/pac198658121677">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac198658121677">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., Ostwald, W., Thorpe, T. E., &#38; Urbain, G. (1909). REPORT OF THE INTERNATIONAL COMMITTEE ON ATOMIC WEIGHTS. 1909. <i>Journal of the American Chemical Society</i>, <i>31</i>(1), 1–6. https://doi.org/10.1021/ja01931a001 <a href="https://doi.org/10.1021/ja01931a001">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja01931a001">Scholia</a></div>
<div class="csl-entry">Coplen, T. B. (2001). Atomic weights of the elements 1999 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>73</i>(4), 667–683. https://doi.org/10.1351/pac200173040667 <a href="https://doi.org/10.1351/pac200173040667">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac200173040667">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 class="csl-entry">Wieser, M. E., &#38; Coplen, T. B. (2010). Atomic weights of the elements 2009 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>83</i>(2), 359–396. https://doi.org/10.1351/pac-rep-10-09-14 <a href="https://doi.org/10.1351/PAC-REP-10-09-14">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/PAC-REP-10-09-14">Scholia</a></div>
</div>

## Turtle

This resource as a file: [Chlorine.ttl](Chlorine.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 skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix unit: <http://qudt.org/vocab/unit/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ciaaw:note-m a ciaaw:Footnote ;
    skos:definition "Modified isotopic compositions may be found in commercially available material because the material has been subjected to some undisclosed or inadvertent isotopic fractionation. Substantial deviations in atomic weight of the element from that given in the table can occur."@en ;
    skos:notation "m" .

ciaaw_draft:AW-Cl-standard-1902 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard-1909 ;
    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:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.45 ] .

ciaaw_draft:AW-Cl-standard a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:issued "2009"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1999 ;
    dcterms:source <https://doi.org/10.1351/PAC-REP-10-09-14> ;
    ciaaw:footnote ciaaw:note-m ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:lowerBound 35.446 ;
            qudt:upperBound 35.457 ;
            ciaaw:significantFiguresLower 5 ;
            ciaaw:significantFiguresUpper 5 ] .

ciaaw_draft:AW-Cl-standard-1909 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard-1925 ;
    dcterms:issued "1909"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1902 ;
    dcterms:source <https://doi.org/10.1021/ja01931a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.46 ] .

ciaaw_draft:AW-Cl-standard-1925 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard-1961 ;
    dcterms:issued "1925"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1909 ;
    dcterms:source <https://doi.org/10.1039/CT9252700913> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.457 ] .

ciaaw_draft:AW-Cl-standard-1961 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard-1985 ;
    dcterms:issued "1961"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1925 ;
    dcterms:source <https://doi.org/10.1021/ja00881a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.453 ;
            qudt:standardUncertainty 0.001 ;
            ciaaw:significantFigures 5 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cl-standard-1985 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard-1999 ;
    dcterms:issued "1985"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1961 ;
    dcterms:source <https://doi.org/10.1351/pac198658121677> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.4527 ;
            qudt:standardUncertainty 0.0009 ;
            ciaaw:significantFigures 6 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cl-standard-1999 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cl-standard ;
    dcterms:issued "1999"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cl-standard-1985 ;
    dcterms:source <https://doi.org/10.1351/pac200173040667> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Chlorine ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 35.453 ;
            qudt:standardUncertainty 0.002 ;
            ciaaw:significantFigures 5 ;
            ciaaw:significantFiguresUncertainty 1 ] .

element:Chlorine a chemrof:ChemicalElement ;
    rdfs:label "chlorine"@en ;
    ciaaw:currentStandardAtomicWeight ciaaw_draft:AW-Cl-standard ;
    ciaaw:hasDeclaration ciaaw_draft:AW-Cl-standard,
        ciaaw_draft:AW-Cl-standard-1902,
        ciaaw_draft:AW-Cl-standard-1909,
        ciaaw_draft:AW-Cl-standard-1925,
        ciaaw_draft:AW-Cl-standard-1961,
        ciaaw_draft:AW-Cl-standard-1985,
        ciaaw_draft:AW-Cl-standard-1999 ;
    ciaaw:hasIsotope ciaaw_draft:Cl-35,
        ciaaw_draft:Cl-37 ;
    ciaaw:standardAtomicWeightLower 35.446 ;
    ciaaw:standardAtomicWeightUpper 35.457 ;
    chemrof:atomic_number 17 ;
    chemrof:symbol "Cl" .
```

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