{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.europium","code":"thing-q1396","url":"https://ver.cy/models/thing/q1396/","name":"europium","alternateNames":["europium-152","europium-161","europium-165","europium-166","europium-130","europium-131","europium-132","europium-133","europium-134","europium-135","europium-136","europium-136m"],"kind":"thing","status":"published","version":"0.2.0-wave.3","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A soft silvery rare earth metal, chemical element 63 and a lanthanide, the most reactive of the rare earths, obtained from monazite and bastnasite; used in red and blue phosphors for displays, lighting and banknote security features, in nuclear control rods and in medical imaging agents.","purpose":"Let an agent explain europium as an element and material, relay its properties, uses, supply and handling information from reference sources, and separate it from other rare earths and from its compounds.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Most reactive rare earth","Red and blue phosphor activator","Divalent and trivalent chemistry","Supply from rare earth processing"],"structure":{"bundles":[{"id":"element","name":"Element","description":"What europium is.","layers":[{"id":"properties","name":"Properties","description":"Properties.","findings":[{"id":"properties-finding","name":"Properties","description":"Properties.","questions":[{"text":"What are the physical, chemical and nuclear properties of europium?","kind":"definition"},{"text":"Is the question about the element, a compound or another rare earth?","kind":"boundary"}]}]},{"id":"production","name":"Production","description":"Ores and separation.","findings":[{"id":"production-finding","name":"Production","description":"Production.","questions":[{"text":"From which ores is europium obtained, and how is it separated?","kind":"provenance"},{"text":"Which entry fits rare earth processing?","kind":"action"}]}]}]},{"id":"use","name":"Use","description":"Applications.","layers":[{"id":"phosphors","name":"Phosphors","description":"Phosphors and security.","findings":[{"id":"phosphors-finding","name":"Phosphors","description":"Phosphors.","questions":[{"text":"How is europium used in displays, lighting and banknote security features?","kind":"provenance"},{"text":"Which entry fits phosphors?","kind":"action"}]}]},{"id":"other","name":"Other","description":"Nuclear and medical uses.","findings":[{"id":"other-finding","name":"Other","description":"Other.","questions":[{"text":"How is europium used in control rods and imaging agents, in general terms?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]}]},{"id":"safety","name":"Safety","description":"Handling and supply.","layers":[{"id":"handling","name":"Handling","description":"Handling.","findings":[{"id":"handling-finding","name":"Handling","description":"Handling.","questions":[{"text":"What handling rules apply to europium metal and compounds?","kind":"provenance"},{"text":"Is the question about a specific workplace, which needs its safety officer?","kind":"boundary"}]}]},{"id":"supply","name":"Supply","description":"Supply.","findings":[{"id":"supply-finding","name":"Supply","description":"Supply.","questions":[{"text":"What are production volumes, producers and criticality assessments, with sources?","kind":"measurement"},{"text":"Which sources and years are cited?","kind":"provenance"}]}]}]},{"id":"context","name":"Context","description":"History and research.","layers":[{"id":"history","name":"History","description":"Discovery.","findings":[{"id":"history-finding","name":"History","description":"History.","questions":[{"text":"How was europium discovered and named?","kind":"provenance"},{"text":"Which entry fits the discoverer?","kind":"action"}]}]},{"id":"research","name":"Research","description":"Research.","findings":[{"id":"research-finding","name":"Research","description":"Research.","questions":[{"text":"What research involves europium, such as luminescent probes?","kind":"provenance"},{"text":"Which entry fits luminescent materials?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Explain europium's properties and uses, citing references.","Relay safety data sheet guidance on its reactivity.","Describe rare earth supply chains with sources and dates."],"mustNot":["Advise storing europium in contact with air or water.","Describe rare earth supply as ethically sourced without evidence.","Disclose details of banknote security features that could aid counterfeiting.","Present supply forecasts as certain."],"requiresHuman":["Any purchase, storage or disposal of europium."]},"ethics":{"considerations":["Rare earth mining harms environments and communities.","Security features protect money from counterfeiters."],"affectedParties":["Mining communities","Workers","The public relying on secure banknotes"]},"owners":{"steward":"The licensed holder of the material.","roles":[],"masterSystems":[]},"relations":[{"target":"Q19569","type":"parent","note":"registry parent class"},{"target":"lanthanide","type":"related","note":"the series"},{"target":"phosphor","type":"related","note":"red and blue emitters"},{"target":"rare earth ore","type":"related","note":"monazite and bastnasite"},{"target":"critical raw material","type":"related","note":"supply policy"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.europium","Wikidata: Q1396 (https://www.wikidata.org/wiki/Q1396)","chemical symbol: Eu","CAS number: 7440-53-1"]},"properties":{"applicability":"required","items":["atomic number: 63","melting point: about 826 degrees C","density: about 5.2 g per cubic centimetre - lowest of the lanthanides","stable isotopes: europium-151 and europium-153 isotopes - europium-151 is very weakly radioactive"]},"recognition":{"applicability":"required","items":["Element 63, lanthanide","Red and blue luminescence in phosphors","Samarium and gadolinium are neighbouring rare earths","Silvery-white soft metal that oxidises quickly in air; compounds glow red or blue under ultraviolet light."]},"capabilities":{"applicability":"required","items":["explain properties and isotopes","explain uses and supply","relay handling information","distinguish from neighbouring rare earths"]},"hazards":{"applicability":"required","items":["Rapid oxidation and reactivity with water","Supply disruption","Environmental impact of rare earth mining"]},"interfaces":{"applicability":"required","items":["Critical raw material lists","Chemical classification and labelling rules","Trade controls on rare earths in some countries"]},"context":{"applicability":"required","items":["Phosphors, security features, control rods and research.","europium metal","europium oxide and other compounds","europium-doped phosphors","europium isotopes","europium in banknote security inks"]}},"sources":[{"title":"Wikidata item Q1396: europium","url":"https://www.wikidata.org/wiki/Q1396","note":"identity and sense of the item"},{"title":"Wikipedia: Europium","url":"https://en.wikipedia.org/wiki/Europium","note":"general description of the item"}],"openQuestions":["Should europium phosphors be a separate entry?","How should supply data be linked?","The registry entry has merged isotope aliases; should they be split off?"],"resources":{"spec":"/models/things/publications/thing-q1396/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1396/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T21:24:54Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-06T19:51:54+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}