Chemistry Dictionary

Chemistry Dictionary explains 683 chemistry terms in clear, plain English, from absolute zero to zwitterion. Every entry gives a short definition with an example, the symbol and unit where they apply, a typeset formula or chemical equation when it helps, and "See also" links to related terms.

What the app covers

• A–Z Dictionary: one page per letter, each with a filter box so you can find any term in seconds
• Browse by Topic: every term grouped into Matter, Measurement and Reactions; Atoms and the Periodic Table; Bonding and Molecular Shape; States of Matter and Solutions; Energy, Rates and Equilibrium; Acids, Bases and Electrochemistry; Elements and Inorganic Chemistry; Organic Chemistry and Biochemistry; Nuclear Chemistry; and Lab Equipment and Techniques
• Key drawings on the topic pages: the periodic table by block, s, p and d orbital shapes, VSEPR molecular shapes, polar molecules and hydrogen bonding, the phase diagram of water, unit cells, energy profiles, the pH scale, titration curves, a galvanic cell, an octahedral complex ion, functional groups, enantiomers, radiation and half-life, laboratory glassware and a distillation set-up
• SI Units and Constants: base and derived units, CODATA 2022 constants from NIST, the gas constant in different units and useful conversions
• Elements: all 118 elements with symbol, name and IUPAC 2021 standard atomic weight
• Common Ions: cations, anions and polyatomic ions with their names and charges
• Prefixes and Greek Letters: SI prefixes, numerical prefixes for naming compounds, carbon-chain stems and the Greek alphabet with its uses in chemistry

Made for studying
• Original definitions written for students
• Typeset formulas and chemical equations that stay sharp on any screen
• Sign conventions stated where books differ
• Search across the whole app and a filter on every letter page
• Dark mode
• Works offline, with no account needed
• Available in 8 languages: English, Español, Português, Français, Deutsch, العربية, हिन्दी and Bahasa Indonesia; terms can be found by their English or translated name

Useful for school chemistry, AP, A-level and IB courses, and introductory college and university chemistry. Definitions and data follow the OpenStax Chemistry 2e textbook, IUPAC recommendations and the NIST CODATA 2022 values.

This app is an independent study aid. It is not affiliated with any exam board, textbook publisher or standards body.

Recent changes:
Completely rewritten: 683 chemistry terms from A to Z with clear new definitions, formulas and examples, plus topic pages with drawings and reference tables (elements, ions, constants). Now in 8 languages: English, Spanish, Portuguese, French, German, Arabic, Hindi and Indonesian; find a term by its English or translated name.