{ "model": { "rank": 4239, "code": "thing-q101395", "model_id": "vr.tr.mass-number", "name": "mass number", "purpose": "Let an agent explain mass number, compute neutron counts and isotope notation, and separate it from atomic number and atomic mass.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QTY", "industry": "", "version": "", "url": "/models/thing/q101395/", "tier": 2, "score": 77, "payload": { "layer": "wikidata", "aliases": [], "aliasCount": 0, "merged": 0, "knownIn": 77, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": "vr.tr.mass-number", "source": { "dataset": "wikidata", "item": "Q101395", "url": "https://www.wikidata.org/wiki/Q101395", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-11T15:32:53Z", "providers": [ "Claude" ], "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify", "pass": 2, "wave": 1, "engine": "claude" }, "metaModel": { "id": "THING-Q101395", "registryId": "vr.tr.mass-number", "name": "mass number", "version": "0.2.0-wave.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QTY" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q101395/", "model": { "registry_id": "vr.tr.mass-number", "name": "mass number", "purpose": "Let an agent explain mass number, compute neutron counts and isotope notation, and separate it from atomic number and atomic mass.", "definition": "The total number of protons and neutrons in an atomic nucleus, denoted A, a dimensionless integer that distinguishes isotopes of the same element and is written as a superscript before the element symbol or after a hyphen, as in carbon-14; it differs from atomic number and from atomic mass.", "what_it_is_for": "Describing nuclei and isotopes.", "affordances": [ "compute neutrons from mass and atomic number", "write isotope notation", "explain differences from atomic mass", "identify isotopes" ], "distinguishing_features": [ "Integer count of nucleons", "Dimensionless", "Defines isotopes with atomic number", "Distinct from atomic mass" ], "appearance": "Not physical; a number in notation.", "visual_identification": [ "Superscript before element symbol", "Hyphenated forms like uranium-235", "Atomic mass is a non-integer average" ], "physical_properties": [], "families_and_kinds": [ "mass numbers of stable isotopes", "mass numbers of radioactive isotopes", "mass numbers in nuclear reactions" ], "related_models": [ { "relation": "is a kind of", "target": "physical quantity", "why": "category" }, { "relation": "is a kind of", "target": "scalar quantity", "why": "category" }, { "relation": "is related to", "target": "atomic number", "why": "related quantity" }, { "relation": "is related to", "target": "amount-of-substance fraction", "why": "isotope abundance context" } ], "identifiers": [], "standards_and_regulation": [ "IUPAC nomenclature for isotopes" ], "failure_modes_and_hazards": [ "Confusing mass number with atomic mass", "Wrong neutron counts", "Misplaced superscripts" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "compute", "name": "Compute", "description": "Nucleon counts.", "rationale": "Simple arithmetic.", "layers": [ { "id": "neutrons", "name": "Neutrons", "description": "Neutron number.", "findings": [ { "id": "neutrons-finding", "name": "Neutrons", "description": "Neutron number.", "questions": [ { "text": "How many neutrons does this isotope have, given mass number and atomic number?", "kind": "measurement" }, { "text": "Which element is it?", "kind": "definition" } ] } ] }, { "id": "notation", "name": "Notation", "description": "Writing isotopes.", "findings": [ { "id": "notation-finding", "name": "Notation", "description": "Notation.", "questions": [ { "text": "How is this isotope written in AZX and hyphen notation?", "kind": "definition" }, { "text": "Which convention does IUPAC recommend?", "kind": "provenance" } ] } ] } ] }, { "id": "distinguish", "name": "Distinguish", "description": "Related quantities.", "rationale": "Terms differ.", "layers": [ { "id": "mass", "name": "Mass", "description": "Atomic mass.", "findings": [ { "id": "mass-finding", "name": "Mass", "description": "Atomic mass.", "questions": [ { "text": "How does mass number differ from atomic mass and relative atomic mass?", "kind": "definition" }, { "text": "Why is atomic mass not an integer?", "kind": "definition" } ] } ] }, { "id": "number", "name": "Number", "description": "Atomic number.", "findings": [ { "id": "number-finding", "name": "Number", "description": "Atomic number.", "questions": [ { "text": "How does mass number differ from atomic number?", "kind": "definition" }, { "text": "Which defines the element?", "kind": "definition" } ] } ] } ] }, { "id": "nuclear", "name": "Nuclear", "description": "Reactions.", "rationale": "Mass number is conserved.", "layers": [ { "id": "conservation", "name": "Conservation", "description": "Balancing equations.", "findings": [ { "id": "conservation-finding", "name": "Conservation", "description": "Conservation.", "questions": [ { "text": "How is mass number conserved in nuclear reactions and decay?", "kind": "definition" }, { "text": "What are the products of this decay?", "kind": "measurement" } ] } ] }, { "id": "stability", "name": "Stability", "description": "Isotope stability.", "findings": [ { "id": "stability-finding", "name": "Stability", "description": "Stability.", "questions": [ { "text": "How does the neutron to proton ratio affect stability?", "kind": "definition" }, { "text": "Where is this isotope on the chart of nuclides?", "kind": "provenance" } ] } ] } ] }, { "id": "teach", "name": "Teach", "description": "Learning.", "rationale": "Common confusions.", "layers": [ { "id": "misconceptions", "name": "Misconceptions", "description": "Errors.", "findings": [ { "id": "misconceptions-finding", "name": "Misconceptions", "description": "Misconceptions.", "questions": [ { "text": "Which misconceptions about mass number are common among students?", "kind": "provenance" }, { "text": "How can they be corrected?", "kind": "action" } ] } ] }, { "id": "examples", "name": "Examples", "description": "Worked examples.", "findings": [ { "id": "examples-finding", "name": "Examples", "description": "Examples.", "questions": [ { "text": "What are worked examples for carbon, uranium and hydrogen isotopes?", "kind": "action" }, { "text": "Which exercises help?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should isotopes be separate entries?", "How should nuclide charts be linked?", "How should notation be rendered?" ], "statistics": { "bundles": 4, "layers": 8, "findings": 8, "questions": 16 } }, "draft": { "generator": "vr.draft.v3", "status": "draft-generated", "researched": false, "archetype": "unit, quantity or measure", "method": "Written from the archetype playbook - what this kind of thing needs beyond identity and provenance - and from the structure that recurred across 6,333 models already researched by two engines. Applied to this entry by rule. No source was read for this thing and no claim here is researched. This entry carries no facets of its own, so they were inferred from its domain - a guess about a whole domain applied to one thing.", "facetsInferred": true, "nextPass": "A researcher replaces this draft with a sourced specification. Treat every sentence below as a proposal to argue with.", "purpose": "Give an agent a durable, checkable way to recognise a mass number, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain mass number, compute neutron counts and isotope notation, and separate it from atomic number and atomic mass.", "characteristics": { "substance": "abstract", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Described in 77 Wikipedia languages, which is a measure of how widely the thing is known, not of how important it is." ], "openQuestionsForResearch": [ "Which of the bundles below does a real task actually need, and which are ceremony?", "What does this thing have that the facets do not capture at all?", "Which neighbouring kind is most often confused with a mass number, and on what evidence are they told apart?" ], "whatItIsMadeOf": "an abstraction with no physical instance", "physicalCharacter": [ "Does nothing on its own; everything it does, something else did to it.", "These come from the domain this entry sits in rather than from the entry itself, so treat them as a first guess about the whole domain applied to one thing." ], "whatCanBeDoneWithIt": [ "observe it, measure it, record its state" ], "howItIsRecognised": [ "Nothing to see: a unit is a convention. What is seen is an instrument reading in it." ], "relatedModels": [], "standing": "Described in 77 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one mass number from another, and a mass number from things that resemble it.", "rationale": "Recognition comes before every other claim. Without stable identity nothing else in the model can be trusted to be about the same thing twice.", "layers": [ { "id": "naming-and-identifiers", "name": "Names and identifiers", "description": "The names this thing goes by and the identifiers that survive translation and time.", "findings": [ { "id": "preferred-name-and-aliases", "name": "Preferred name, aliases and local names", "description": "Which name to use, which names mean the same thing, and which merely sound similar.", "questions": [ { "id": "preferred-name-and-aliases-q01", "text": "What identifies and describes the name of a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "preferred-name-and-aliases-q02", "text": "Who or what asserted this about the name of a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "preferred-name-and-aliases-q03", "text": "What may an agent decide or do once the name of a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "stable-identifiers", "name": "Stable identifiers and external keys", "description": "Identifiers that keep pointing at this kind of thing across systems and languages.", "questions": [ { "id": "stable-identifiers-q01", "text": "What identifies and describes an identifier for a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stable-identifiers-q02", "text": "Who or what asserted this about an identifier for a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stable-identifiers-q03", "text": "What may an agent decide or do once an identifier for a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "classification-and-granularity", "name": "Classification and granularity", "description": "Where a mass number sits among kinds, and how finely a task needs to cut it.", "findings": [ { "id": "kind-and-parents", "name": "Kind, parents and neighbouring kinds", "description": "The classes this thing belongs to and the ones it is next to.", "questions": [ { "id": "kind-and-parents-q01", "text": "What identifies and describes the kind of a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "kind-and-parents-q02", "text": "Who or what asserted this about the kind of a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "kind-and-parents-q03", "text": "What may an agent decide or do once the kind of a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "distinguishing-features", "name": "Distinguishing features", "description": "What separates a mass number from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "distinguishing-features-q02", "text": "Who or what asserted this about what distinguishes a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "distinguishing-features-q03", "text": "What may an agent decide or do once what distinguishes a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "state-and-lifecycle", "name": "State and lifecycle", "description": "The states a mass number passes through and the events that move it between them.", "rationale": "Most decisions about a thing depend on what state it is in now, which is a claim with a time on it, not a property.", "layers": [ { "id": "lifecycle-stages", "name": "Lifecycle stages", "description": "From coming into existence to ceasing to be one of these.", "findings": [ { "id": "stages-and-transitions", "name": "Stages and transitions", "description": "The stages worth naming and what moves a mass number between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stages-and-transitions-q02", "text": "Who or what asserted this about the lifecycle of a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stages-and-transitions-q03", "text": "What may an agent decide or do once the lifecycle of a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "observations-and-status", "name": "Observations and current status", "description": "What is observed about a mass number, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a mass number is recorded so that it can be superseded rather than overwritten.", "questions": [ { "id": "observation-record-q01", "text": "What identifies and describes an observation of a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "observation-record-q02", "text": "Who or what asserted this about an observation of a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "observation-record-q03", "text": "What may an agent decide or do once an observation of a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definition-and-realisation", "name": "Definition, dimension and realisation", "description": "What mass number is defined as and how it is realised in practice.", "rationale": "A unit is not the quantity it measures, and its definition has a history that older data still depends on.", "layers": [ { "id": "definition", "name": "Definition and dimension", "description": "The defining relation and the quantity it measures.", "findings": [ { "id": "definition-record", "name": "Definition, body and date", "description": "What defines it now, and what defined it before.", "questions": [ { "id": "definition-record-q01", "text": "How is mass number defined, by which body, and since when?", "kind": "definition" }, { "id": "definition-record-q02", "text": "What was the previous definition, and what data still depends on it?", "kind": "provenance" } ] } ] }, { "id": "conversion", "name": "Conversion and compatibility", "description": "Relations to other units, exact or approximate.", "findings": [ { "id": "conversion-record", "name": "Conversions and their exactness", "description": "Factors, and whether each is exact by definition.", "questions": [ { "id": "conversion-record-q01", "text": "What conversions relate mass number to other units, and which are exact by definition?", "kind": "measurement" }, { "id": "conversion-record-q02", "text": "Where does rounding a conversion change a decision, and how should that be recorded?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a mass number came from and when it held.", "rationale": "A claim without a source and a time cannot be superseded, only overwritten, and an agent that overwrites loses the ability to explain itself.", "layers": [ { "id": "source-and-authority", "name": "Source and authority", "description": "Who said it, on what evidence, and how strongly.", "findings": [ { "id": "claim-provenance", "name": "Claim provenance and confidence", "description": "The authority behind each claim about a mass number and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "claim-provenance-q02", "text": "Who or what asserted this about a claim about a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "claim-provenance-q03", "text": "What may an agent decide or do once a claim about a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "time-and-versions", "name": "Time, versions and supersession", "description": "When a claim was true, when it was learnt, and what replaced it.", "findings": [ { "id": "validity-and-supersession", "name": "Validity period and supersession", "description": "How an old claim about a mass number is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a mass number, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "validity-and-supersession-q02", "text": "Who or what asserted this about the validity of a claim about a mass number, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "validity-and-supersession-q03", "text": "What may an agent decide or do once the validity of a claim about a mass number is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 4, "layers": 8, "findings": 10, "questions": 28 } } } }