copper(I) oxide

chemical compound
ChemicalSubstance type_of_chemical_entity Q407709
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Summary

copper(I) oxide is a type of chemical entity[1]. It ranks in the top 5% of type of chemical entity entities by monthly Wikipedia readership (1,728 views/month).[2]

Key Facts

  • Canonical SMILES: [O-2].[Cu+].[Cu+][3], O=[Cu].[Cu][4]
  • Chemical formula: Cu₂O[5]
  • Subclass of: copper oxide[6]
  • Commons category: Copper(I) oxide[7]
  • Color: red brown[8]
  • Crystal system: cubic crystal system[9]
  • Point group: cubic-hexoctahedral[10]
  • Space group: space group Pn-3m[11]
  • Refractive index: 2.85[12]
  • Described by source: Meyers Konversations-Lexikon, 4th edition (1885–1890)[13]
  • Density: 6.0[14]
  • Molar fusion enthalpy: 64.22[15]
  • Mass: 141.854[16], 141.85410962[17]
  • Melting point: 1244[18]
  • Boiling point: 2073.15[19]
  • Decomposition point: 1800[20]
  • Has part(s) of the class: oxygen[21], copper[22]
  • Standard molar entropy: 129.96[23], 92.37[24]
  • Standard enthalpy of formation: -112.0[25], -170.71[26]
  • Safety classification and labelling: NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response[27]

Why It Matters

copper(I) oxide has Wikipedia articles in 26 language editions, a strong signal of global cultural recognition.[28] It is known by 56 alternative names across languages and contexts.[29]

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [3] ↑ . wikidata.org.
  2. [4] ↑ . wikidata.org.
  3. [5] ↑ . wikidata.org.
  4. [6] ↑ . wikidata.org.
  5. [7] ↑ . wikidata.org.
  6. [8] ↑ . wikidata.org.
  7. [9] ↑ . wikidata.org.
  8. [10] ↑ . wikidata.org.
  9. [11] ↑ . wikidata.org.
  10. [12] ↑ . wikidata.org.
  11. [13] ↑ . wikidata.org.
  12. [14] ↑ . wikidata.org.
  13. [15] ↑ . wikidata.org.
  14. [16] ↑ . wikidata.org.
  15. [17] ↑ . wikidata.org.
  16. [18] ↑ . wikidata.org.
  17. [19] ↑ . wikidata.org.
  18. [20] ↑ . wikidata.org.
  19. [21] ↑ . wikidata.org.
  20. [22] ↑ . wikidata.org.
  21. [23] ↑ . wikidata.org.
  22. [24] ↑ . wikidata.org.
  23. [25] ↑ . wikidata.org.
  24. [26] ↑ . wikidata.org.
  25. [27] ↑ . wikidata.org.

Class ancestry

  1. [1] ↑ . Wikidata. wikidata.org.

Aggregate / graph-position facts

  1. [2] ↑ . Wikimedia Foundation. dumps.wikimedia.org.
  2. [28] ↑ . Wikidata sitelinks. wikidata.org.
  3. [29] ↑ . Wikidata aliases. wikidata.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). copper(I) oxide. Retrieved October 13, 2026, from https://4ort.xyz/entity/copper-i-oxide
MLA “copper(I) oxide.” 4ort.xyz Knowledge Graph, 4ort.xyz, 13 Oct. 2026, https://4ort.xyz/entity/copper-i-oxide.
BibTeX @misc{4ortxyz_copper-i-oxide_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{copper(I) oxide}}, year = {2026}, url = {https://4ort.xyz/entity/copper-i-oxide}, note = {Accessed: 2026-10-13}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): copper(I) oxide — https://4ort.xyz/entity/copper-i-oxide (retrieved 2026-10-13)

Canonical URL: https://4ort.xyz/entity/copper-i-oxide · Last refreshed:

Edit History

Rolling log of changes to this entity's Wikidata record. Values shown reflect the current state of each edited property — follow the history link to see the precise diff for any edit.

  1. 20d ago · KrBot bot · 2026-09-26 view diff on Wikidata ↗
    Zvg number → 4790
    "/* wbsetclaimvalue:1| */ Zvg number: 4790, см. / see [[Template:Autofix|autofix]] на / on [[Property talk:P679]]"
  2. 23d ago · Mrwdat3 · 2026-09-23 view diff on Wikidata ↗
    Has part(s) → —
    Zvg number → 4790
    Standard enthalpy of formation → {'amount': '-112.0'}, {'amount': '-170.71'}
    Has part(s) of the class → oxygen, copper
    + 2 other properties edited (see Wikidata diff for full list)
    "/* wbcreateclaim-create:1| */ Zvg number: 004790, [[:toollabs:quickstatements/#/batch/275042|batch #275042]]"
  3. 7w ago · Baum64 · 2026-08-23 view diff on Wikidata ↗
    Has part(s) → —
    Has part(s) of the class → oxygen, copper
    "/* wbcreateclaim-create:1| */ Has part(s) of the class: oxygen, [[:toollabs:quickstatements/#/batch/269324|batch #269324]]"
  4. 8w ago · Baum64 · 2026-08-18 view diff on Wikidata ↗
    Cod id → 9007497
    Space group → space group Pn-3m
    Boiling point → {'amount': '+2073.15'}
    "/* wbcreateclaim-create:1| */ Cod id: 9007497, [[:toollabs:quickstatements/#/batch/269136|batch #269136]]"
  5. 17w ago · Nabbegat · 2026-06-19 view diff on Wikidata ↗
    Density → {'amount': '+6.0'}
    Color → red brown
    Decomposition point → {'amount': '+1800'}
    Has parts → —
    + 17 other properties edited (see Wikidata diff for full list)
    "/* wbeditentity-update-languages-short:0||tr */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/37300|batch #37300]]"
Live feed via Wikidata EventStreams. New edits appear within minutes of being made on Wikidata.