Periodic Table and Chemistry

Checked data, with its sources in plain sight. Periodic Table is the chemistry reference that fits in your pocket: all 118 elements, 147 reactions, 22 lab tables, quizzes and eleven calculators. No ads, no account, works offline.

DATA YOU CAN TRUST
• Checked against PubChem, IUPAC, NIST and the IAEA. The sources are listed in the app, under More › Data sources.
• A value with no reliable published measurement shows as unknown (---), never made up. Elements 119 to 124 are marked as hypothetical.

ELEVEN LAB CALCULATORS
Free in their basic modes, with history: molar mass and composition, empirical formula, inorganic and organic nomenclature (IUPAC), equation balancing (redox too) with ΔH°, ΔS°, ΔG° and K, solutions (molarity, dilution, molality), gases, colligative properties, equilibrium with ICE tables, pH, electrochemical cells and analytical statistics.
With Pro: stoichiometry, mass percent and ppm, gas mixtures, vapor pressure, Le Chatelier with numbers, buffers, the Nernst equation, combustion analysis, confidence intervals and outlier tests (Dixon's Q and Grubbs).

QUIZZES BUILT FROM THE DATA
Questions are generated from the app's own data, and every answer shows the value it rests on, with a link to where that value lives. Eight topics, three levels. Practice is free and unlimited; the timed exam and spaced review are Pro.

EVERY ELEMENT IN DEPTH
• Over 70 physical, thermal, atomic, crystal, safety (NFPA 704) and abundance properties, from the Earth and the Sun to the human body. The advanced ones with Pro.
• Orbital diagram with Hund's rule, unpaired electrons and the ground-state term. If the real configuration breaks the Madelung rule, it says so.
• Shell model, emission spectrum, natural isotopes and real photos of 97 elements, credited.
• Touch and hold a value to copy it; tap its name to see what it means.
• Favorites, your own notes, and two or three elements side by side.

TWO TAPS TO ANY VALUE
• Search by name, symbol, atomic number, Latin or English name, CAS number or family.
• The full table, with family filters and a heat map.
• 38 sortable lists (28 free) and a trends chart.
• 147 reactions with their conditions, oxidation-state changes, precipitates and ΔH°, ΔS°, ΔG° and K at 25 °C, ready to balance in one tap.
• A 173-term glossary linked to the data.
• 22 tables, 10 free (solubility, reduction potentials, acids and bases, Ksp, thermodynamic data, cryoscopic and ebullioscopic constants…) and 12 with Pro (ionization energies, van der Waals, critical values for t, F, Q and Grubbs, Henry's law…).

ON ALL YOUR DEVICES
iPhone, iPad and Mac with Apple silicon. An Apple Watch app with all 124 elements that works without your iPhone. Element of the Day (also on the Lock Screen) and Favorites widgets. Siri, Shortcuts and Spotlight. In 20 languages, with VoiceOver, larger text, Dark Mode and a shape for each family if you can't tell the colors apart.

FREE AND PRO, NO FINE PRINT
Free: the table, search, each element's core data, 10 tables, 28 lists, reactions, the glossary, quiz practice, all eleven calculators in their basic modes, the watch app, widgets and three themes.
Pro: the other 12 tables and 10 lists; advanced data such as magnetic and electrical properties, the critical point and every radioactive isotope; timed exam, spaced review and stats; the calculators' advanced modes; PDF export; and ten more themes.

Pay once for Pro and it's yours for life, no subscription needed. If you prefer, there are also monthly and yearly plans; all three unlock the same things. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period, and are managed in your Apple Account settings.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://periodictable.echandia.app/privacidad/#en