Periodic Table vs Combinatorics PRO

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 26.1 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/

Finally there is the app that provides all 6 variations of combinatorics with step by step solutions: - permutation without repetition: Arranging elements without repetition. - permutation with repetition: Arranging elements with repetition. - combination without repetition: Selecting elements without considering the order. - combination with repetition: Selecting elements with consideration of the order. - variation without repetition: Arranging elements with fixed length without repetition. - variation with repetition: Arranging elements with fixed length with repetition. You only have to enter your values k and n. The values must be entered as natural numbers. The only exception is the k value for permutation with repitition. This requires several k values, which must be entered separated by semicolons. All calculations are stored in the history. The final solution can be shared. [ Contents ] - all 6 variations of combinatorics - results are calculated and shown in detail - history to save the input - detailed solution - natural numbers are supported - no ads! [ Usage ] - there are fields for entering values using a special keyboard - multiple k values can be entered using the semicolon key - press the check mark button at the bottom right to start the calculation - if values are missing, the corresponding field is highlighted in yellow - if the values are incorrect, the affected field will be highlighted in red - a short message explains why a value is incorrect - the entries in the history can be deleted or sorted - if you select an entry in the history, it will be automatically loaded for the calculation - the whole history can be deleted by pressing a button - solutions can be shared