Corrections & Transparency

How to report an error, how corrections are handled, and the log of material corrections.

Found something wrong or unclear? We welcome correction reports — especially for numbers, equations, units, conditions, hazards, links, or captions. Substantive errors are corrected transparently and logged below.

How to report an error

Visible path on every scientific page

Each lesson, formula, glossary entry, element/compound/reaction page and the periodic table includes a “Report an error / Correction?” link to this page and to /contact. Calculator pages also link to corrections.

What to include

  • URL or path (e.g., /elements/o or /lessons/ideal-gas-law)
  • Exact quote or screenshot
  • Your suggested fix and, ideally, a primary source (IUPAC, CIAAW, NIST, PubChem, SDS lot)
  • Your contact (optional) if you'd like a reply

Fastest routes: Contact form → · Feedback → · or email via the contact page. For safety-critical errors (wrong PPE, disposal, hazard statement), mark the subject line "Safety correction" so it is escalated.

How we handle corrections

  1. Triage — safety-critical reports first; others within days. Confirm definitions, units, state, T/P, isotope, allotrope, and scale match.
  2. Verify against the source hierarchy (IUPAC → CIAAW → NIST → PubChem → ACS/GHS/SDS → primary literature) at the exact property.
  3. Decide per the conflict-resolution rules — preserve intervals/bracketed mass numbers, show qualified ranges where needed, never silently average.
  4. Fix in content or dataset, record reviewer and lastReviewedAt, and add a change note if the fix is substantive (numeric value, equation, hazard, or answer key).
  5. Publish — change notes appear below and on the affected page's last-reviewed metadata. Trivial typographic or style deploys do not create correction entries.
  6. Notify — if the reporter left contact details, we reply with the outcome.

Last reviewed / updated semantics

On any page, Last reviewed means a real editorial or chemistry review occurred on that date.Updated is used only when a substantive scientific change was made and logged. Routine code or style deployments do not alter review dates. See editorial policy for gate definitions.

Material correction log

We do not display a fake correction history. If no material corrections have yet been logged, we state that clearly — as is the case here.

Status as of 2026-08-23

No material correction has yet been logged since the Prompt 08 rebuild. The items below reflect systematic improvements applied site-wide during the August 2026 review (datasets, provenance, and policy), each verified against the stated sources.

  • 2026-08-23 — Compound dataset harmonization. Replaced placeholder physical properties (1.0 g/cm³ / 300 K / 400 K for every compound) with sourced, condition-qualified values for 37 compounds (density, melting/boiling points at 1 atm or decomposition noted). Sources: NIST Chemistry WebBook, PubChem compound records, CIAAW where molar mass is derived. Verified: src/data/compounds.ts via validate-data.mjs. Reviewer: Editorial Review Board.
  • 2026-08-23 — Source model upgrade. Expanded references collection to typed Source Record Model (sourceType, status, scopeNote, licenseNote, archiveUrl, replacement linkage, access/review dates). Added hierarchy entries: ciaaw-atomic-weights-2021, iupac-periodic-table, pubchem-periodic-table, acs-safety-ramp, unece-ghs, osha-chemical, etc. See /sources.
  • 2026-08-23 — Safety framework rebuild. Created /safety (RAMP-based) and hardened /lab-safety with contextual tripwire: no universal PPE statements, no medical advice beyond emergency referral, no unsupervised recipes for flame/pressure/toxic gases/reactive metals/oxidizers.
  • 2026-08-23 — Provenance plumbing. Extended MeasuredValue and AtomicWeight with optional per-property provenance (sourceId, pinpoint, lastVerified, transformNote) in src/lib/chemistry/datasets-types.ts; dataset-level provenanceNotes available for grouped-property provenance.

Future material corrections will be inserted here with date, scope (path or dataset id), original vs corrected value, reason/sources, and reviewer. Trivial style/copy edits remain unlogged but may bump updatedAt.

Nothing to correct yet — but please report if you find one

The absence of a past correction does not imply infallibility. If you spot an issue, the reporting path above is the most direct way to trigger a reviewed correction. We log only real, reviewed corrections — never fabricated entries.

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