{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.alkaline-earth-metal","code":"thing-q19563","url":"https://ver.cy/models/thing/q19563/","name":"alkaline earth metal","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"An alkaline earth metal is any of the six IUPAC Group 2 s-block elements (Be, Mg, Ca, Sr, Ba, Ra) with a closed ns² valence configuration, which form predominantly M²⁺ cations and generally basic oxides historically called alkaline earths, except that beryllium oxide is amphoteric, with metallic and ionic character increasing down the group.","purpose":"Enable an AI agent to recognise an alkaline earth metal, assess the condition of a particular material and determine which handling, transformation or use decisions its recorded evidence supports.","scope":{"in":["Identification of the Group 2 element and evidence supporting that identification","Elemental-metal content, impurities and boundaries between metal, alloy and compound","Physical form, phase and surface alteration of a material specimen","Element-specific chemical behaviour under recorded environmental conditions","Material properties and hazards that constrain handling, storage, processing and use"],"out":["Detailed identities and behaviour of alkaline earth compounds, minerals and dissolved ions","Alloy design and properties of mixtures that require their own material models","Mining, refining and manufacturing workflows as complete processes","Biological roles, exposure assessment and clinical management","Radioactive decay chains, radiation facilities and waste-management systems"],"boundaries":[]},"distinguishingFeatures":["Elemental identity must resolve to Be, Mg, Ca, Sr, Ba or Ra; metallic appearance or alkaline reaction products alone do not establish membership.","Group 2 membership distinguishes these elements from Group 1 alkali metals; similar names or water reactivity are insufficient identification tests.","Evidence must distinguish elemental metal from an oxide, hydroxide, salt or dissolved ion containing the same element; detecting calcium, for example, does not establish calcium metal.","A material containing an alkaline earth element must be assessed for alloy or mixture status before the whole material is classified as that elemental metal.","Weak or absent reaction in a particular test does not alone exclude Group 2 identity; element, surface condition and test conditions must be recorded."],"structure":{"bundles":[{"id":"group-two-identity","name":"Group 2 identity and material boundary","description":"Establishes which alkaline earth element is represented and whether the material is actually in elemental-metal form.","layers":[{"id":"element-membership","name":"Element membership","description":"Resolves identity within the six Group 2 elements.","findings":[{"id":"supported-element-assignment","name":"Supported element assignment","description":"Records the proposed elemental identity and the evidence needed to accept it.","questions":[{"text":"Which of Be, Mg, Ca, Sr, Ba or Ra is represented, and does the record describe an element type or a particular specimen?","id":"supported-element-assignment-q01","kind":"definition"},{"text":"Which analytical result or traceable material record supports that identity, and are there contradictory observations?","id":"supported-element-assignment-q02","kind":"provenance"}]}]},{"id":"metal-compound-alloy-boundary","name":"Metal, compound and alloy boundary","description":"Separates elemental metal from materials that merely contain the element.","findings":[{"id":"elemental-metal-status","name":"Elemental-metal status","description":"Establishes whether the specimen is predominantly metal, a metal with alteration products or a material requiring a neighbouring model.","questions":[{"text":"What evidence distinguishes elemental metal from oxides, hydroxides, salts or other compounds containing the same element?","id":"elemental-metal-status-q01","kind":"measurement"},{"text":"Do alloying constituents or compound phases require a linked alloy, mixture or compound model?","id":"elemental-metal-status-q02","kind":"boundary"}]}]}]},{"id":"metal-form-and-condition","name":"Metal form and condition","description":"Captures the bulk and surface states that determine how a specimen behaves.","layers":[{"id":"bulk-form-and-phase","name":"Bulk form and phase","description":"Records geometry, particle scale and thermal state.","findings":[{"id":"condition-specific-physical-properties","name":"Condition-specific physical properties","description":"Connects the specimen's form and measured properties to the conditions under which they apply.","questions":[{"text":"What are the material's physical form, dimensions or particle-size distribution, temperature and phase?","id":"condition-specific-physical-properties-q01","kind":"measurement"},{"text":"Which density, conductivity or mechanical-property evidence applies to this element, purity, form and temperature?","id":"condition-specific-physical-properties-q02","kind":"provenance"}]}]},{"id":"surface-film-and-alteration","name":"Surface film and alteration","description":"Distinguishes the metallic interior from surface products and contamination.","findings":[{"id":"surface-controlled-condition","name":"Surface-controlled condition","description":"Records surface alteration and whether it explains changes in observed behaviour.","questions":[{"text":"What surface film or contamination has been identified, and what is known about its extent or thickness?","id":"surface-controlled-condition-q01","kind":"measurement"},{"text":"What evidence establishes whether the surface layer limits further reaction under the recorded conditions?","id":"surface-controlled-condition-q02","kind":"provenance"},{"text":"At what observed extent of alteration should the specimen be represented as metal plus reaction products rather than as an unqualified metal?","id":"surface-controlled-condition-q03","kind":"boundary"}]}]}]},{"id":"element-specific-reactivity","name":"Element-specific reactivity","description":"Organises evidence about chemical behaviour without treating all alkaline earth metals as interchangeable.","layers":[{"id":"air-and-water-response","name":"Air and water response","description":"Records behaviour during contact with oxygen, humidity, liquid water or steam.","findings":[{"id":"environment-conditioned-reaction","name":"Environment-conditioned reaction","description":"Connects reaction observations to the specific element, form, surface and exposure conditions.","questions":[{"text":"What reaction, temperature change, gas evolution or material loss was observed during a documented air, moisture, water or steam exposure?","id":"environment-conditioned-reaction-q01","kind":"measurement"},{"text":"Which element, particle scale, surface condition, temperature and exposure duration does that observation cover?","id":"environment-conditioned-reaction-q02","kind":"boundary"},{"text":"What additional evidence is needed before using the observation to judge a proposed exposure?","id":"environment-conditioned-reaction-q03","kind":"action"}]}]},{"id":"chemical-contact-and-conversion","name":"Chemical contact and conversion","description":"Assesses proposed contacts and transformations using evidence specific to the metal.","findings":[{"id":"supported-chemical-compatibility","name":"Supported chemical compatibility","description":"Records compatibility and transformation evidence for identified contacting substances.","questions":[{"text":"Which documented evidence covers contact with the proposed acid, base, solvent, gas or solid at the intended concentration and temperature?","id":"supported-chemical-compatibility-q01","kind":"provenance"},{"text":"Which reaction products, heat release or gas generation must be accounted for before permitting the proposed contact?","id":"supported-chemical-compatibility-q02","kind":"action"},{"text":"When conversion occurs, which resulting compounds or mixtures need their own linked models?","id":"supported-chemical-compatibility-q03","kind":"boundary"}]}]}]},{"id":"handling-and-use-eligibility","name":"Handling and use eligibility","description":"Relates the metal's identity and current condition to storage, processing and application decisions.","layers":[{"id":"element-and-form-specific-controls","name":"Element and form-specific controls","description":"Links hazards and controls to the actual metal, including dust-generating operations and relevant isotopes.","findings":[{"id":"supported-handling-envelope","name":"Supported handling envelope","description":"Records the conditions under which proposed handling or storage is supported by applicable evidence.","questions":[{"text":"Which current material-specific sources establish the controls for this element and form, including beryllium exposure or radium radiological controls where applicable?","id":"supported-handling-envelope-q01","kind":"provenance"},{"text":"Are the proposed atmosphere, protective medium and container materials supported for this metal's condition and intended storage duration?","id":"supported-handling-envelope-q02","kind":"action"},{"text":"Would cutting, grinding or heating change the form or exposure conditions enough to require reassessment?","id":"supported-handling-envelope-q03","kind":"action"}]}]},{"id":"fitness-for-intended-operation","name":"Fitness for intended operation","description":"Tests whether the recorded specimen can support a stated processing step or material function.","findings":[{"id":"use-specific-acceptance","name":"Use-specific acceptance","description":"Connects intended performance to verified composition, surface condition and physical properties.","questions":[{"text":"Which limits on metal content, impurities, surface alteration and physical form does the intended operation require?","id":"use-specific-acceptance-q01","kind":"boundary"},{"text":"Which measurements demonstrate that this specimen meets those limits?","id":"use-specific-acceptance-q02","kind":"measurement"},{"text":"Can the proposed operation proceed on the available evidence, or which unresolved condition requires further characterisation?","id":"use-specific-acceptance-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-kinds","name":"Kinds and varieties","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these kinds and varieties hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these standards and regulation hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these real-world use hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these typical measurements hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-regional-variation","name":"Regional variation","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these regional variation hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-regional-variation-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of alkaline earth metal this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Describe properties of the Group 2 elements, citing chemical references.","Report safety data from official safety sheets."],"mustNot":["Advise handling reactive metals or their compounds outside a properly equipped setting.","Understate the toxicity of beryllium or the radioactivity of radium.","Help anyone use these elements to harm people.","Dispose of them or their compounds with ordinary waste."],"requiresHuman":["Approving storage or use of radioactive or highly toxic members on a site."]},"ethics":{"considerations":["Calcium and magnesium are essential to life, while beryllium and radium are dangerous.","Radium exposure harmed workers in the past."],"affectedParties":["Workers and students","People near chemical sites"]},"owners":{"steward":"Nobody owns the element group; each holder answers for safe use.","roles":[],"masterSystems":[]},"relations":[{"target":"Q11426","type":"parent","note":"registry parent class"},{"target":"Q2512777","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.alkaline-earth-metal","Wikidata: Q19563 (https://www.wikidata.org/wiki/Q19563)"]},"properties":{"applicability":"required","items":["Elemental identity: beryllium | magnesium | calcium | strontium | barium | radium | unresolved","Identity evidence: Links to analytical results, material certificates or other identification records","Elemental-metal mass fraction: Mass fraction or mass %, with method, uncertainty and sampling basis","Impurity and alloying composition: Constituent mass fractions, with detection limits","Physical form: bulk piece | sheet | ribbon | turnings | powder | other recorded form","Particle size or exposed surface: Particle-size distribution in µm or mm; exposed area in m² or specific surface area in m²/kg","Surface condition: Freshly exposed | characterised surface film | visibly altered | contaminated | unknown, with evidence","Temperature and phase: Temperature in K or °C; solid | liquid | vapour | mixed | unresolved","Contact environment: Links to contacting gases, liquids, solids or protective media, with humidity, temperature and duration where relevant","Isotopic and radiological characterisation: Isotope fractions and activity in Bq or Bq/g where relevant; unknown explicitly recorded"]},"recognition":{"applicability":"required","items":["Fresh surfaces of several members appear silvery or gray, but this appearance is shared by many other metals.","Oxidation can dull or coat exposed surfaces, so surface color alone cannot establish group membership.","Element symbols and verified composition records distinguish these materials more reliably than their visible appearance."]},"capabilities":{"applicability":"required","items":["Identify a specimen as a particular Group 2 metal or flag insufficient or conflicting evidence.","Assess whether alteration or mixing requires representation as a composite, alloy or compound.","Compare measured behaviour with references matched to element, form and conditions.","Evaluate proposed storage media and contact materials against documented compatibility evidence.","Determine whether cutting, grinding, heating or chemical transformation is supported by the recorded material state and applicable controls.","Select additional characterisation needed before accepting a material for an intended use."]},"hazards":{"applicability":"required","items":["Beryllium dust causes chronic lung disease.","Radium is radioactive."]},"interfaces":{"applicability":"required","items":["Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations."]},"context":{"applicability":"required","items":["Alkaline earth metals are encountered in chemistry, metallurgy and materials research as elements and constituents of compounds.","Their compounds occur in minerals and manufactured materials, but suitability for a use depends on the particular element and chemical form."]}},"sources":[{"title":"Chemistry of the Elements, 2nd ed. (N. N. Greenwood and A. Earnshaw; Butterworth-Heinemann)","url":"","note":"Group 2 electronic structure, periodic trends, reactivity with water and air, and the historical meaning of alkaline earths as the oxides."},{"title":"Nomenclature of Inorganic Chemistry, IUPAC Recommendations 2005 (Red Book) (IUPAC; Royal Society of Chemistry)","url":"","note":"Official IUPAC Group 2 numbering and the membership of the group as Be, Mg, Ca, Sr, Ba and Ra."},{"title":"CRC Handbook of Chemistry and Physics (CRC Press / Taylor & Francis)","url":"","note":"Typical ranges for ionization energy, density, melting point, ionic radius and standard potentials of the Group 2 metals."},{"title":"Alkaline earth metal (Wikimedia Foundation)","url":"https://en.wikipedia.org/wiki/Alkaline_earth_metal","note":"Conventional membership of the group, common uses, and the distinction from alkali metals and rare-earth metals."},{"title":"Wikidata item Q19563: alkaline earth metal","url":"https://www.wikidata.org/wiki/Q19563","note":"identity and sense of the item"}],"openQuestions":["Does the registry intend this entry to own the Group 2 family only, individual metal specimens, or both through linked element-specific models?","Which authoritative references and analytical methods should establish elemental-metal content separately from total elemental content?","Which element-specific evidence is needed to characterise surface films and their effects across bulk, finely divided and heated material?","What documented criteria should govern transitions from an elemental-metal specimen to an alloy, mixture or substantially converted material?","Which current sources should govern handling and use decisions for each element and form, particularly beryllium-containing dust and radium specimens?"],"resources":{"spec":"/models/things/publications/thing-q19563/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q19563/spec.json"],"providers":["Codex","Grok"],"researchStatus":"unreviewed","generatedAt":"2026-09-07T11:15:18Z","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 2026-10-07T12:16:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}