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

# thorium

| Property | Value |
| --- | --- |
| Symbol | Th |
| Atomic number | 90 |
| IRI | `https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/Thorium` |
| Wikidata | [Q1115](https://www.wikidata.org/wiki/Q1115) |

## Standard atomic weight

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| 232.0377(4) | 2013 | [10.1515/pac-2015-0305](https://doi.org/10.1515/pac-2015-0305) | Current | [`AW-Th-standard`](../id/AW-Th-standard.md) |
| 232.038 06(2) | 2005 | [10.1351/pac200678112051](https://doi.org/10.1351/pac200678112051) | Deprecated, see [`AW-Th-standard`](../id/AW-Th-standard.md) | [`AW-Th-standard-2005`](../id/AW-Th-standard-2005.md) |
| 232.0381(1) | 1969 | [10.1351/pac197021010091](https://doi.org/10.1351/pac197021010091) | Deprecated, see [`AW-Th-standard-2005`](../id/AW-Th-standard-2005.md) | [`AW-Th-standard-1969`](../id/AW-Th-standard-1969.md) |
| 232.038 | 1961 | [10.1021/ja00881a001](https://doi.org/10.1021/ja00881a001) | Deprecated, see [`AW-Th-standard-1969`](../id/AW-Th-standard-1969.md) | [`AW-Th-standard-1961`](../id/AW-Th-standard-1961.md) |
| 232.05 | 1953 | [10.1039/JR9540004713](https://doi.org/10.1039/JR9540004713) | Deprecated, see [`AW-Th-standard-1961`](../id/AW-Th-standard-1961.md) | [`AW-Th-standard-1953`](../id/AW-Th-standard-1953.md) |
| 232.12 | 1931 | [10.1039/JR9310001617](https://doi.org/10.1039/JR9310001617) | Deprecated, see [`AW-Th-standard-1953`](../id/AW-Th-standard-1953.md) | [`AW-Th-standard-1931`](../id/AW-Th-standard-1931.md) |
| 232.15 | 1920 | [10.1021/ja02233a600](https://doi.org/10.1021/ja02233a600) | Deprecated, see [`AW-Th-standard-1931`](../id/AW-Th-standard-1931.md) | [`AW-Th-standard-1920`](../id/AW-Th-standard-1920.md) |
| 232.4 | 1911 | [10.1021/ja01928a001](https://doi.org/10.1021/ja01928a001) | Deprecated, see [`AW-Th-standard-1920`](../id/AW-Th-standard-1920.md) | [`AW-Th-standard-1911`](../id/AW-Th-standard-1911.md) |
| 232.42 | 1909 | [10.1021/ja01931a001](https://doi.org/10.1021/ja01931a001) | Deprecated, see [`AW-Th-standard-1911`](../id/AW-Th-standard-1911.md) | [`AW-Th-standard-1909`](../id/AW-Th-standard-1909.md) |
| 232.5 | 1902 | [10.1007/BF01370337](https://doi.org/10.1007/BF01370337) | Deprecated, see [`AW-Th-standard-1909`](../id/AW-Th-standard-1909.md) | [`AW-Th-standard-1902`](../id/AW-Th-standard-1902.md) |

Notes: [g](#note-g)

## Isotopes

| A | Representative isotopic composition | Year | Source | Declaration | ChEBI | Wikidata |
| --- | --- | --- | --- | --- | --- | --- |
| [230](../id/Th-230.md) | 0.0002(2) | — | — | [`Abundance-Th230`](../id/Abundance-Th230.md) | — | [Q14755481](https://www.wikidata.org/wiki/Q14755481) |
| [232](../id/Th-232.md) | 0.9998(2) | — | — | [`Abundance-Th232`](../id/Abundance-Th232.md) | — | [Q7885290](https://www.wikidata.org/wiki/Q7885290) |

Notes: [g](#note-g)

## 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.

## 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">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., 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">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">International atomic weights, 1953. (1954). <i>Journal of the Chemical Society (Resumed)</i>, 4713. https://doi.org/10.1039/jr9540004713 <a href="https://doi.org/10.1039/JR9540004713">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1039/JR9540004713">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">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: [Thorium.ttl](Thorium.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-g a ciaaw:Footnote ;
    skos:definition "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."@en ;
    skos:notation "g" .

ciaaw_draft:AW-Th-standard-1902 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-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:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.5 ] .

ciaaw_draft:AW-Th-standard a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:issued "2013"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-2005 ;
    dcterms:source <https://doi.org/10.1515/pac-2015-0305> ;
    ciaaw:footnote ciaaw:note-g ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.0377 ;
            qudt:standardUncertainty 0.0004 ;
            ciaaw:significantFigures 7 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Th-standard-1909 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1911 ;
    dcterms:issued "1909"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1902 ;
    dcterms:source <https://doi.org/10.1021/ja01931a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.42 ] .

ciaaw_draft:AW-Th-standard-1911 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1920 ;
    dcterms:issued "1911"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1909 ;
    dcterms:source <https://doi.org/10.1021/ja01928a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.4 ] .

ciaaw_draft:AW-Th-standard-1920 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1931 ;
    dcterms:issued "1920"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1911 ;
    dcterms:source <https://doi.org/10.1021/ja02233a600> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.15 ] .

ciaaw_draft:AW-Th-standard-1931 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1953 ;
    dcterms:issued "1931"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1920 ;
    dcterms:source <https://doi.org/10.1039/JR9310001617> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.12 ] .

ciaaw_draft:AW-Th-standard-1953 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1961 ;
    dcterms:issued "1953"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1931 ;
    dcterms:source <https://doi.org/10.1039/JR9540004713> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.05 ] .

ciaaw_draft:AW-Th-standard-1961 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-1969 ;
    dcterms:issued "1961"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1953 ;
    dcterms:source <https://doi.org/10.1021/ja00881a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.038 ] .

ciaaw_draft:AW-Th-standard-1969 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard-2005 ;
    dcterms:issued "1969"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1961 ;
    dcterms:source <https://doi.org/10.1351/pac197021010091> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.0381 ;
            qudt:standardUncertainty 0.0001 ;
            ciaaw:significantFigures 7 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Th-standard-2005 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Th-standard ;
    dcterms:issued "2005"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Th-standard-1969 ;
    dcterms:source <https://doi.org/10.1351/pac200678112051> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Thorium ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 232.03806 ;
            qudt:standardUncertainty 0.00002 ;
            ciaaw:significantFigures 8 ;
            ciaaw:significantFiguresUncertainty 1 ] .

element:Thorium a chemrof:ChemicalElement ;
    rdfs:label "thorium"@en ;
    ciaaw:currentStandardAtomicWeight ciaaw_draft:AW-Th-standard ;
    ciaaw:hasDeclaration ciaaw_draft:AW-Th-standard,
        ciaaw_draft:AW-Th-standard-1902,
        ciaaw_draft:AW-Th-standard-1909,
        ciaaw_draft:AW-Th-standard-1911,
        ciaaw_draft:AW-Th-standard-1920,
        ciaaw_draft:AW-Th-standard-1931,
        ciaaw_draft:AW-Th-standard-1953,
        ciaaw_draft:AW-Th-standard-1961,
        ciaaw_draft:AW-Th-standard-1969,
        ciaaw_draft:AW-Th-standard-2005 ;
    ciaaw:hasIsotope ciaaw_draft:Th-230,
        ciaaw_draft:Th-232 ;
    ciaaw:standardAtomicWeightUncertainty 0.0004 ;
    ciaaw:standardAtomicWeightValue 232.0377 ;
    chemrof:atomic_number 90 ;
    chemrof:symbol "Th" .
```

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