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

# caesium

| Property | Value |
| --- | --- |
| Symbol | Cs |
| Atomic number | 55 |
| IRI | `https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/Caesium` |
| Wikidata | [Q1108](https://www.wikidata.org/wiki/Q1108) |

## Standard atomic weight

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| 132.905 451 96(6) | 2013 | [10.1515/pac-2015-0305](https://doi.org/10.1515/pac-2015-0305) | Current | [`AW-Cs-standard`](../id/AW-Cs-standard.md) |
| 132.905 4519(2) | 2005 | [10.1351/pac200678112051](https://doi.org/10.1351/pac200678112051) | Deprecated, see [`AW-Cs-standard`](../id/AW-Cs-standard.md) | [`AW-Cs-standard-2005`](../id/AW-Cs-standard-2005.md) |
| 132.905 45(2) | 1995 | [10.1351/pac199668122339](https://doi.org/10.1351/pac199668122339) | Deprecated, see [`AW-Cs-standard-2005`](../id/AW-Cs-standard-2005.md) | [`AW-Cs-standard-1995`](../id/AW-Cs-standard-1995.md) |
| 132.905 43(5) | 1985 | [10.1351/pac198658121677](https://doi.org/10.1351/pac198658121677) | Deprecated, see [`AW-Cs-standard-1995`](../id/AW-Cs-standard-1995.md) | [`AW-Cs-standard-1985`](../id/AW-Cs-standard-1985.md) |
| 132.9054(1) | 1971 | [10.1351/pac197230030637](https://doi.org/10.1351/pac197230030637) | Deprecated, see [`AW-Cs-standard-1985`](../id/AW-Cs-standard-1985.md) | [`AW-Cs-standard-1971`](../id/AW-Cs-standard-1971.md) |
| 132.9055(1) | 1969 | [10.1351/pac197021010091](https://doi.org/10.1351/pac197021010091) | Deprecated, see [`AW-Cs-standard-1971`](../id/AW-Cs-standard-1971.md) | [`AW-Cs-standard-1969`](../id/AW-Cs-standard-1969.md) |
| 132.905 | 1961 | [10.1021/ja00881a001](https://doi.org/10.1021/ja00881a001) | Deprecated, see [`AW-Cs-standard-1969`](../id/AW-Cs-standard-1969.md) | [`AW-Cs-standard-1961`](../id/AW-Cs-standard-1961.md) |
| 132.91 | 1934 | [10.1039/JR9340000499](https://doi.org/10.1039/JR9340000499) | Deprecated, see [`AW-Cs-standard-1961`](../id/AW-Cs-standard-1961.md) | [`AW-Cs-standard-1934`](../id/AW-Cs-standard-1934.md) |
| 132.81 | 1909 | [10.1021/ja01931a001](https://doi.org/10.1021/ja01931a001) | Deprecated, see [`AW-Cs-standard-1934`](../id/AW-Cs-standard-1934.md) | [`AW-Cs-standard-1909`](../id/AW-Cs-standard-1909.md) |
| 132.9 | 1904 | [10.1021/ja01991a001](https://doi.org/10.1021/ja01991a001) | Deprecated, see [`AW-Cs-standard-1909`](../id/AW-Cs-standard-1909.md) | [`AW-Cs-standard-1904`](../id/AW-Cs-standard-1904.md) |
| 133 | 1902 | [10.1007/BF01370337](https://doi.org/10.1007/BF01370337) | Deprecated, see [`AW-Cs-standard-1904`](../id/AW-Cs-standard-1904.md) | [`AW-Cs-standard-1902`](../id/AW-Cs-standard-1902.md) |


## Isotopes

| A | Representative isotopic composition | Year | Source | Declaration | ChEBI | Wikidata |
| --- | --- | --- | --- | --- | --- | --- |
| [133](../id/Cs-133.md) | 1 | — | — | [`Abundance-Cs133`](../id/Abundance-Cs133.md) | — | [Q2327948](https://www.wikidata.org/wiki/Q2327948) |

## Bibliography

<div class="csl-bib-body">
<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 1971. (1972). <i>Pure and Applied Chemistry</i>, <i>30</i>(3–4), 637–650. https://doi.org/10.1351/pac197230030637 <a href="https://doi.org/10.1351/pac197230030637">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac197230030637">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">Baxter, G. P., Curie, Mme. P., Lebeau, P., Hönigschmid, O., &#38; Meyer, R. J. (1934). Fourth Report of the Committee on Atomic Weights of the International Union of Chemistry. <i>J. Chem. Soc.</i>, <i>0</i>(0), 499–512. https://doi.org/10.1039/jr9340000499 <a href="https://doi.org/10.1039/JR9340000499">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1039/JR9340000499">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. (1996). Atomic weights of the elements 1995 (Technical Report). <i>Pure and Applied Chemistry</i>, <i>68</i>(12), 2339–2359. https://doi.org/10.1351/pac199668122339 <a href="https://doi.org/10.1351/pac199668122339">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac199668122339">Scholia</a></div>
<div class="csl-entry">Meija, J., Coplen, T. B., Berglund, M., Brand, W. A., De Bièvre, P., Gröning, M., Holden, N. E., Irrgeher, J., Loss, R. D., Walczyk, T., &#38; Prohaska, T. (2016). Atomic weights of the elements 2013 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>88</i>(3), 265–291. https://doi.org/10.1515/pac-2015-0305 <a href="https://doi.org/10.1515/pac-2015-0305">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1515/pac-2015-0305">Scholia</a></div>
<div class="csl-entry">REPORT OF THE INTERNATIONAL COMMITTEE ON ATOMIC WEIGHTS. (1904). <i>Journal of the American Chemical Society</i>, <i>26</i>(1), 1–4. https://doi.org/10.1021/ja01991a001 <a href="https://doi.org/10.1021/ja01991a001">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja01991a001">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. (2006). Atomic weights of the elements 2005 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>78</i>(11), 2051–2066. https://doi.org/10.1351/pac200678112051 <a href="https://doi.org/10.1351/pac200678112051">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac200678112051">Scholia</a></div>
</div>

## Turtle

This resource as a file: [Caesium.ttl](Caesium.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-Cs-standard-1902 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1904 ;
    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:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 133.0 ] .

ciaaw_draft:AW-Cs-standard a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:issued "2013"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-2005 ;
    dcterms:source <https://doi.org/10.1515/pac-2015-0305> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.90545196 ;
            qudt:standardUncertainty 0.00000006 ;
            ciaaw:significantFigures 11 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cs-standard-1904 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1909 ;
    dcterms:issued "1904"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1902 ;
    dcterms:source <https://doi.org/10.1021/ja01991a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.9 ] .

ciaaw_draft:AW-Cs-standard-1909 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1934 ;
    dcterms:issued "1909"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1904 ;
    dcterms:source <https://doi.org/10.1021/ja01931a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.81 ] .

ciaaw_draft:AW-Cs-standard-1934 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1961 ;
    dcterms:issued "1934"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1909 ;
    dcterms:source <https://doi.org/10.1039/JR9340000499> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.91 ] .

ciaaw_draft:AW-Cs-standard-1961 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1969 ;
    dcterms:issued "1961"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1934 ;
    dcterms:source <https://doi.org/10.1021/ja00881a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.905 ] .

ciaaw_draft:AW-Cs-standard-1969 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1971 ;
    dcterms:issued "1969"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1961 ;
    dcterms:source <https://doi.org/10.1351/pac197021010091> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.9055 ;
            qudt:standardUncertainty 0.0001 ;
            ciaaw:significantFigures 7 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cs-standard-1971 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1985 ;
    dcterms:issued "1971"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1969 ;
    dcterms:source <https://doi.org/10.1351/pac197230030637> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.9054 ;
            qudt:standardUncertainty 0.0001 ;
            ciaaw:significantFigures 7 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cs-standard-1985 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-1995 ;
    dcterms:issued "1985"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1971 ;
    dcterms:source <https://doi.org/10.1351/pac198658121677> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.90543 ;
            qudt:standardUncertainty 0.00005 ;
            ciaaw:significantFigures 8 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cs-standard-1995 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard-2005 ;
    dcterms:issued "1995"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1985 ;
    dcterms:source <https://doi.org/10.1351/pac199668122339> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.90545 ;
            qudt:standardUncertainty 0.00002 ;
            ciaaw:significantFigures 8 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Cs-standard-2005 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Cs-standard ;
    dcterms:issued "2005"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Cs-standard-1995 ;
    dcterms:source <https://doi.org/10.1351/pac200678112051> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Caesium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 132.9054519 ;
            qudt:standardUncertainty 0.0000002 ;
            ciaaw:significantFigures 10 ;
            ciaaw:significantFiguresUncertainty 1 ] .

element:Caesium a chemrof:ChemicalElement ;
    rdfs:label "caesium"@en ;
    ciaaw:currentStandardAtomicWeight ciaaw_draft:AW-Cs-standard ;
    ciaaw:hasDeclaration ciaaw_draft:AW-Cs-standard,
        ciaaw_draft:AW-Cs-standard-1902,
        ciaaw_draft:AW-Cs-standard-1904,
        ciaaw_draft:AW-Cs-standard-1909,
        ciaaw_draft:AW-Cs-standard-1934,
        ciaaw_draft:AW-Cs-standard-1961,
        ciaaw_draft:AW-Cs-standard-1969,
        ciaaw_draft:AW-Cs-standard-1971,
        ciaaw_draft:AW-Cs-standard-1985,
        ciaaw_draft:AW-Cs-standard-1995,
        ciaaw_draft:AW-Cs-standard-2005 ;
    ciaaw:hasIsotope ciaaw_draft:Cs-133 ;
    ciaaw:standardAtomicWeightUncertainty 0.00000006 ;
    ciaaw:standardAtomicWeightValue 132.90545196 ;
    chemrof:atomic_number 55 ;
    chemrof:symbol "Cs" .
```

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