Periodic Table: Chemistry 3D2.5.5 - App Store

Chemistry Explorer brings an interactive periodic table, 2D/3D molecules, an equation balancer, and 29 chemistry tools into one focused app for students, teachers, and curious minds.

PERIODIC TABLE, PERFECTED
. All 118 elements in a clean, color-coded layout
. Tap any element for properties, isotopes, spectra, and real-world uses
. Instant search by name, symbol, or atomic number

MOLECULES IN 2D & 3D
. Enter any valid SMILES to generate a structure with RDKit
. Search 352 curated molecules by name or formula
. Calculate molecular weight, logP, TPSA, and more on device
. Rotate and explore structures in interactive 3D

OFFLINE MOLECULE DATABASE
. Chemistry Pro unlocks all 8,000 included compounds
. On iOS 26.4 or later, Pro can download the complete 467,735-compound library through Apple

29 TOOLS FOR CHEMISTRY, 25 OF THEM FREE
. Balance equations; calculate molar mass and stoichiometry; explore pH/pOH, buffers, gas laws, kinetics, equilibrium, solutions, and more

DESIGNED FOR FOCUS
. Chemistry calculations and molecular processing run on device; no account required
. English, Français, 简体中文, 繁體中文, 日本語, Español, Deutsch, Português, 한국어, Русский, and Tiếng Việt
. Optimized for iPhone and iPad

Twenty-five of the twenty-nine tools are free, the reaction predictor and every reference table among them, plus two SMILES builds a day and all 352 curated molecules. Chemistry Pro is available as monthly, yearly, or lifetime access and unlocks the other four tools - buffers, equilibrium, reaction rate, and Arrhenius - along with unlimited SMILES builds and all 8,000 bundled compounds. Paid users of the original app keep Legacy Pro.

Daily free advanced-tool choices: 1. Reopening a chosen tool that day is unlimited.
Usage and crash reporting are on by default. You can turn them off in Settings. No advertising ID is collected.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Version History • Explore electron clouds, electron shells and molecules in landscape, with free zoom and controls you can hide.

• Updated atomic weights and strengthened calculation checks, with clearer model limits and source references. 2.5.5 Oct 4 • With Chemistry Pro, the Molecules page now also searches the offline molecule database as you type, including the complete library once downloaded.
• The free tier is now the 352 curated molecules, with the same count shown throughout the app. Chemistry Pro searches all 8,000 included compounds and the optional complete library. 2.5.4 Sep 25 • Fixed a crash that could occur when closing a 3D view.
• Usage and crash reporting are on by default. You can turn them off in Settings. No advertising ID is collected. 2.5.3 Sep 19 • Fixed a crash when opening All Tools and improved translations throughout the app.
• Daily free advanced-tool choices: 1. Reopening a chosen tool that day is unlimited.
• Free accounts can build up to 2 new molecules from SMILES each day. Reopening a saved molecule does not use a build.
• Usage and crash reporting are off by default. You can choose to share them in Settings. No advertising ID is collected. 2.5.2 Sep 16 • Chemistry Explorer now speaks Korean, Russian, and Vietnamese — the interface, all 118 elements, 352 molecules, the reaction library, the glossary, and the reference tables.
• Element and molecule names follow the standards each language teaches: the Korean Chemical Society's 2005 nomenclature, IUPAC Russian names, and the international names of Vietnam's 2018 curriculum.
• Corrected molecule names in the offline library that a data import had attached to the wrong compound. 2.5.1 Sep 12 • Explore functional groups, molecular geometry, crystal coordination, orbital cutaways and linked hydrogen transitions.
• Compare shared molecular structures in 2D and 3D, follow periodic trends and explore the redesigned similarity map.
• New interactive strong-acid titration curve and a particle view that explains dilution.
• More reliable purchase activation and restoration, with clearer subscription pricing.

• Twenty-five of the twenty-nine Lab tools are now free, the reaction predictor among them, with no daily limit.
• Build five new molecules from SMILES every day. Reopening one you already saved does not use a build.
• Reaction search now matches exact formula, charge, and phase, and filters by the reactant or the product side.
• Selected reactions show the net ionic equation beside the molecular one, each with its own source and hand-off to the balancer.
• Fixed: full-width characters from a Chinese or Japanese keyboard broke the balancer, SMILES, and molar mass. Ｈ２ＳＯ４ now reads the same as H2SO4.
• Fixed a freeze when opening All Tools from the Today and Search tabs.
• Common molecules in the offline library now show their names in your language. 2.5.0 Sep 9 • Apple Watch support: browse all 118 elements, explore richer properties, see the element of the day, and view favorites from your iPhone.
• Practice with short quizzes, daily streaks, and a review of questions you missed.
• Create notes linked to elements, molecules, and reactions; organize them with tags and export them.
• Compare molecular structures and properties side by side.
• Improved scientific reference details, accessibility, and reliability. 2.4.0 Sep 5 • Improved Search and offline molecule-library reliability, including safer asynchronous results and clearer download availability.
• Strengthened scientific evidence details for crystal structures and element media.
• Improved purchase restoration, paywall accessibility, and large-text layouts.
• Fixed edge cases around app prompts, molecule export cancellation, and background state changes. 2.3.1 Aug 31 • Build molecules from fragments in the new Molecule Builder, with real-time valence checks, a live structure canvas, and save/history support.
• Take on a new daily molecule-building challenge from Today.
• Molecule search now recognizes displayed formulas, while equivalent SMILES structures match the same catalog entry more reliably.
• Stoichiometry, dilution, and ideal gas calculators are now free for everyone.
• Improved Lab favorites and overall reliability. 2.3.0 Aug 28 • Every element is now open: emission spectra, the complete isotope browser, 3D shell and electron-cloud models, atomic radii, oxidation states, and ionization ladders are free for all 118.
• New Chemistry Glossary: 151 terms across nine areas, each with a definition, where it applies, related terms, and a cited source — searchable by term, symbol, or meaning.
• The Reaction Library grows from 18 to 68 reactions; every equation and classification traces to a named section of OpenStax Chemistry 2e or IUPAC.
• The periodic table adds a 32-column long-form layout and can be colored by block (s/p/d/f) or by state at room temperature.

Enjoying Chemistry Explorer? A rating takes a few seconds and helps other students find it. 2.2.0 Aug 19 • ChemKeys now offers dedicated single, double, and triple bond keys; delta and reaction arrows remain in the quick strip.
• Live SMILES search accepts ChemKeys display notation such as C≡C and ring subscripts while preserving the text you typed.
• Search results distinguish INPUT from CANONICAL SMILES only when they differ, and molecule details link directly to the SMILES Guide.
• The Today molecule pauses while sheets are open, reducing unnecessary animation work. 2.1.5 Aug 18 • Equations now balance exact decimal compositions, reject malformed formulas, and handle extreme input without crashing.
• All Tools opens faster on older devices: offscreen cards load lazily and the Today molecule stops rotating before navigation.
• Molecule search and Pro access stay correct across downloads, entitlement changes, foreground refreshes, and cancelled RDKit work.
• ChemKeys adds positive and negative charge signs in superscript mode, and C60 geometry is more accurate. 2.1.4 Aug 13 • Tap the speaker beside any element to hear its name. French users are clearly told that English element names are currently used.
• Hydrogen through neon keep the full experience free; Pro unlocks advanced spectra, isotope browsing, and 3D/cloud models for all 118 elements.
• Pro offers now appear after meaningful use, explain the feature requested, and show complete-database OS requirements before purchase.
• Strengthened source-backed chemical safety data and resolved the identity of (+)-limonene against authoritative records. 2.1.3 Aug 2 • Browse 3,557 ground-state nuclides with half-lives, decay modes, abundance, and source details.
• Explore a source-checked reaction library and send equations directly to the balancer.
• View authoritative element specimen and mineral images with attribution and licensing.
• Fixed the All Tools freeze and improved Lab responsiveness. 2.1.2 Jul 28 • Search 8,000 source-ranked compounds offline with Chemistry Pro.
• On iOS 26.4 or later, download the complete 467,735-record library on demand through Apple.
• Find compounds by name, formula, CID, InChIKey, or SMILES.
• Generate structures and descriptors on device with RDKit, with clear source and safety guidance. 2.1.1 Jul 27 • Search 8,000 source-ranked compounds offline with Chemistry Pro.
• On iOS 26.4 or later, download the complete 467,735-record library on demand through Apple.
• Find compounds by name, formula, CID, InChIKey, or SMILES.
• Generate structures and descriptors on device with RDKit, with clear source and safety guidance. 2.1.0 Jul 25 • Improved Home Screen widget contrast for clear, readable text.
• Fixed live SMILES entitlement refresh and strengthened Pro gating.
• Corrected mixed-side equation balancing plus pOH and Arrhenius teaching visuals.
• Added clearer data provenance and direct email support. 2.0.1 Jul 19 • New Chemistry Pro options: monthly, yearly, or lifetime
• Legacy Pro unlock for paid users of the original app
• Advanced lab tools, live molecule generation, and reference workflows
• Performance and stability improvements 2.0.0 Jul 15 Add Dilution Calculator, Reconstitution Calculator, etc. 1.1.1 03/13/2024 Add Dilution Calculator, Reconstitution Calculator, etc. 1.1.0 03/13/2024 Fixed bugs. 1.0.1 02/28/2024 1.0.0 02/27/2024