{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.praseodymium","code":"thing-q1386","url":"https://ver.cy/models/thing/q1386/","name":"praseodymium","alternateNames":["praseodymium-121","praseodymium-122","praseodymium-123","praseodymium-124","praseodymium-125","praseodymium-126","praseodymium-127","praseodymium-127m","praseodymium-128","praseodymium-129","praseodymium-129m","praseodymium-130"],"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 chemical element with symbol Pr and atomic number 59, a soft, silvery, malleable lanthanide that tarnishes in air and forms green trivalent compounds; praseodymium is used in high-strength magnesium alloys for aircraft engines, in neodymium magnets as an additive, in yellow glass and ceramic pigments and in welders goggles, is recovered from monazite and bastnasite, and has one stable isotope, praseodymium-141.","purpose":"Let an agent identify praseodymium and its properties, relay production, uses, isotopes and history from reference sources, relay safety information, and distinguish it from neighbouring lanthanides.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Green salts","Single stable isotope Pr-141","Magnet and alloy additive","Optical filtering"],"structure":{"bundles":[{"id":"identify","name":"Identify","description":"What praseodymium is.","layers":[{"id":"properties","name":"Properties","description":"Properties.","findings":[{"id":"properties-finding","name":"Properties","description":"Properties.","questions":[{"text":"What are the physical and chemical properties of praseodymium?","kind":"definition"},{"text":"Is the question about praseodymium or a neighbouring lanthanide?","kind":"boundary"}]}]},{"id":"isotopes","name":"Isotopes","description":"Isotopes.","findings":[{"id":"isotopes-finding","name":"Isotopes","description":"Isotopes.","questions":[{"text":"Which isotopes exist, and which are stable?","kind":"definition"},{"text":"Which entry fits the specific isotope?","kind":"action"}]}]}]},{"id":"source","name":"Source","description":"Occurrence and production.","layers":[{"id":"occurrence","name":"Occurrence","description":"Occurrence.","findings":[{"id":"occurrence-finding","name":"Occurrence","description":"Occurrence.","questions":[{"text":"Where does praseodymium occur, and how is it separated from other rare earths?","kind":"provenance"},{"text":"Which entry fits rare earth mining?","kind":"action"}]}]},{"id":"supply","name":"Supply","description":"Supply.","findings":[{"id":"supply-finding","name":"Supply","description":"Supply.","questions":[{"text":"Who produces praseodymium, and how is it traded, with sources?","kind":"measurement"},{"text":"Which sources are cited?","kind":"provenance"}]}]}]},{"id":"use","name":"Use","description":"Uses and safety.","layers":[{"id":"uses","name":"Uses","description":"Uses.","findings":[{"id":"uses-finding","name":"Uses","description":"Uses.","questions":[{"text":"How is praseodymium used in magnets, alloys, glass and pigments?","kind":"provenance"},{"text":"Which entry fits neodymium magnet?","kind":"action"}]}]},{"id":"safety","name":"Safety","description":"Safety.","findings":[{"id":"safety-finding","name":"Safety","description":"Safety.","questions":[{"text":"What hazards does praseodymium present, and how is it handled?","kind":"provenance"},{"text":"Is the user asking about a personal exposure, which needs a clinician or poison centre?","kind":"boundary"}]}]}]},{"id":"context","name":"Context","description":"History.","layers":[{"id":"discovery","name":"Discovery","description":"Discovery.","findings":[{"id":"discovery-finding","name":"Discovery","description":"Discovery.","questions":[{"text":"How was praseodymium separated from didymium by Auer von Welsbach in 1885, and how was it named?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]},{"id":"teach","name":"Teach","description":"Teaching.","findings":[{"id":"teach-finding","name":"Teach","description":"Teaching.","questions":[{"text":"How is praseodymium used to teach lanthanide chemistry?","kind":"provenance"},{"text":"Which entry fits the periodic table?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Describe praseodymium, its compounds and uses from reference sources.","Report supply sources and certification where records exist."],"mustNot":["Handle fine praseodymium metal powder without fire controls.","Dispose of rare earth processing waste into water or soil.","Hide the origin of rare earth supplies in reporting.","Present uncertain toxicity as settled in either direction."],"requiresHuman":["Handling bulk metal powders in a workplace."]},"ethics":{"considerations":["Rare earth extraction often leaves polluted land and water near the mines.","Supply concentration makes praseodymium subject to trade pressure."],"affectedParties":["Mine and refinery workers","Communities near processing","Users of magnets and alloys"]},"owners":{"steward":"Nobody owns the element; mine operators, refiners and holders answer for the material.","roles":[],"masterSystems":[]},"relations":[{"target":"Q19569","type":"parent","note":"registry parent class"},{"target":"lanthanide","type":"related","note":"in registry terms"},{"target":"rare earth element","type":"related","note":"in general terms"},{"target":"cerium","type":"related","note":"element 58"},{"target":"neodymium","type":"related","note":"element 60"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.praseodymium","Wikidata: Q1386 (https://www.wikidata.org/wiki/Q1386)","symbol: Pr","CAS: 7440-10-0"]},"properties":{"applicability":"required","items":["atomic number: 59 Z","standard atomic weight: 140.908 u","melting point: 931 degrees C","density: 6.77 g/cm3"]},"recognition":{"applicability":"required","items":["Element 59, symbol Pr","Lanthanide with green compounds","Cerium and neodymium are the neighbouring lanthanides","A soft, silvery metal that develops a green oxide coating in air."]},"capabilities":{"applicability":"required","items":["relay properties and isotopes","explain production and uses","relay safety information","distinguish from other lanthanides"]},"hazards":{"applicability":"required","items":["Flammability of fine metal","Supply concentration","Confusion with neodymium in magnet contexts"]},"interfaces":{"applicability":"required","items":["Chemical safety data sheets","Rare earth trade and export rules","Critical raw material listings"]},"context":{"applicability":"required","items":["Alloys, magnets, pigments and optical glass.","praseodymium metal and alloys","praseodymium compounds such as the oxide and chloride","isotopes from praseodymium-121 to praseodymium-159, with Pr-141 stable","praseodymium in magnets, glass and pigments"]}},"sources":[{"title":"Wikidata item Q1386: praseodymium","url":"https://www.wikidata.org/wiki/Q1386","note":"identity and sense of the item"},{"title":"Wikipedia: Praseodymium","url":"https://en.wikipedia.org/wiki/Praseodymium","note":"general description of the item"}],"openQuestions":["Should isotopes be separate entries?","How should reference data be linked?","The registry entry has merged aliases naming isotopes; should they be split off?"],"resources":{"spec":"/models/things/publications/thing-q1386/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1386/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T23:13:43Z","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}}