Sources & Editorial Standards

Chemistry Dictionary is a reference site, so accuracy matters more than anything else. This page explains where our information comes from, how definitions are checked, and which authoritative sources we rely on. If a definition and a primary source ever disagree, the primary source wins.

How definitions are checked

Every entry is written in plain language and then checked against established chemistry before it is published. Our process includes:

• Formula and structure verification. Chemical formulas, molecular structures, and identifiers for compounds are cross-checked against PubChem, the open chemical database maintained by the U.S. National Institutes of Health.
• Element data. Atomic numbers, atomic masses, electron configurations, electronegativity, ionization energies, and oxidation states are taken from standard reference data consistent with the IUPAC Periodic Table and the Royal Society of Chemistry.
• Naming and terminology. We follow the naming conventions and definitions set by the International Union of Pure and Applied Chemistry (IUPAC), including terms defined in the IUPAC Compendium of Chemical Terminology (the Gold Book).
• Physical constants and properties. Melting and boiling points, thermodynamic values, and spectroscopic data are checked against the NIST Chemistry WebBook from the U.S. National Institute of Standards and Technology.

Authoritative references we rely on

These are the primary, freely accessible sources behind our entries. We link directly to many of them from individual term pages so you can read the underlying data yourself.

• IUPAC — the global authority on chemical nomenclature, terminology, and standardized data.
• IUPAC Gold Book — the definitive compendium of chemical terminology.
• PubChem (NIH / NCBI) — structures, formulas, identifiers, and properties for millions of compounds.
• NIST Chemistry WebBook — thermochemical, spectroscopic, and physical property data.
• Royal Society of Chemistry Periodic Table — element data, history, and uses.
• CAS Common Chemistry — verified substance names and CAS Registry Numbers.

We also draw on widely used general and organic chemistry textbooks for the standard classroom conventions taught at the high-school and introductory-college level, which is the audience we write for.

What we are, and what we are not

Chemistry Dictionary is an educational reference for students, teachers, and the curious. Our definitions are written to help you understand and use a term correctly. They are not a substitute for a primary research source, a safety data sheet, or professional or medical advice. For laboratory safety, regulatory, or clinical decisions, always consult the appropriate authoritative source directly.

Corrections and feedback

We would rather be corrected than be wrong. If you find an error, an outdated value, or an unclear explanation, please tell us. We read every message and update entries when needed, and we note when an entry was last reviewed.