Molecule builder: learn chemistry atom by atom
BuildMolecules lets you create molecular structures atom by atom and understand chemical bonds in an interactive way. Perfect for students, teachers, and science enthusiasts.
BuildMolecules Main Features
Everything you need to build molecules and learn chemistry through an interactive visual experience
Drag-and-Drop Builder
Build molecules by dragging atoms from your palette into the workspace. Works smoothly with both touch and mouse controls.
Single, Double and Triple Bonds
Connect atoms with single, double or triple bonds that snap into place when you release them. BuildMolecules checks each atom's valence so you learn which structures are chemically correct.
118 Elements and 11 Isotopes
Explore the complete periodic table in 10 categories (non-metals, halogens, noble gases, alkali metals, transition metals, lanthanides, actinides and more) plus isotopes such as deuterium, carbon-14 and uranium-235. Each atom shows its atomic number, mass, valences and electron configuration.
Molecule Recognition
Build a compound and verify it instantly against a database of more than 430 real molecules: from water and carbon dioxide to acids, salts, organic compounds and biomolecules.
Molecule Library
Browse more than 430 molecules with their physical state and melting and boiling points, unlock hints to discover new ones and load any of them onto the board to study or modify it.
Lewis Structure Viewer
Visualize the Lewis structure of more than 400 molecules, with atoms, bonds and lone electron pairs clearly drawn on screen.
Chemistry Quizzes
Test your knowledge with more than 400 questions in over 100 quizzes, from basic concepts to advanced levels, and earn rewards for every quiz you pass.
Chemistry Notebook
238 theory cards across 22 topics (atomic structure, bonding, reactions, thermochemistry, organic chemistry, nuclear chemistry and more), organized by level and linked to the quizzes.
Learn While You Play
Level up as a scientist, keep your daily streak, complete daily challenges, unlock new elements, recruit mentors, build your campus and forge alloys.
🔧 Build Molecules in Action
A quick look at everything you can do with Build Molecules
Who is BuildMolecules for?
Find out why students, teachers, and science enthusiasts around the world use BuildMolecules
High School and University Students
Visualize real molecules interactively while you study. Build H₂O, CO₂, glucose, and see how bonds form in seconds.
Chemistry Teachers
Show molecular structures dynamically in class. Load predefined molecules, explain bond types, and support your lessons with clear, on-screen visualizations.
Exam Preparation
Review molecular formulas and Lewis structures before exams by building molecules yourself. Learn by doing, not just memorizing.
Science Enthusiasts
Ever wondered what atoms make up sugar, caffeine, or alcohol? Build and instantly identify the molecules surrounding you every day.
Exploring the Periodic Table
With 118 elements in 10 categories, discover each atom's properties — symbol, name, and valence — and experiment with how they combine.
Self-Directed Learning
No prior knowledge required. Start with simple molecules and progress to more complex structures at your own pace, guided by the built-in library.
What hooked me was unlocking elements little by little. Every molecule you verify correctly makes you want to try the next one. Without ever meaning to study chemistry, I just can't stop until I unlock the next one.
This app has been very useful in class as I can use it on the interactive whiteboard to show how bonds and atoms combine to create molecules. The notebook is also a great idea. I recommend it as support material, as it serves as a summary to reinforce what has been learned in class.
The interface is intuitive, it runs smoothly and you can tell it's well crafted. On top of that, it's useful whether you're studying or just curious about chemistry.
I have no formal chemistry background, but I've spent hours exploring the periodic table and building molecules. It's addictive to discover that sugar is just C, H, and O combined in a specific way.
I had a chemical formula exam and had practiced so much with BuildMolecules that I felt very confident going in. Building molecules yourself is so much better than memorizing formulas.
My daughter was struggling with chemistry at school. We used BuildMolecules together and in one afternoon she understood bond types better than she had all semester. Highly recommended.
Frequently Asked Questions
Everything you need to know about BuildMolecules
Yes, BuildMolecules works completely offline. You can build and visualize molecules without needing internet access. All core features are available without a connection.
Yes. The app includes a built-in library with pre-designed molecules you can explore, study, and use as a starting point for building your own structures. Perfect for learning with real-world examples.
You can use all 118 elements of the periodic table plus 11 isotopes. You start with H, C, N, O and S and unlock the rest as you progress. From simple molecules like water (H₂O) to complex organic compounds, the app recognizes more than 430 real molecules.
The atom palette lets you easily select elements from the periodic table to add to your molecule. Each atom is displayed with its symbol and bonding properties, making it simple and intuitive to build molecular structures.
Yes. BuildMolecules calculates and displays the molecular formula automatically as you build your molecule, following the Hill system: carbon first, then hydrogen, and then the remaining elements in alphabetical order.
BuildMolecules is perfect for high school and university students, chemistry teachers looking for a visual teaching tool, and anyone curious about how molecules work. It's educational, intuitive, and free.
BuildMolecules is available in 16 languages: English, Spanish, French, German, Italian, Portuguese, Turkish, Indonesian, Arabic, Hebrew, Urdu, Hindi, Bengali, Marathi, Tamil and Telugu.
Ads allow us to keep BuildMolecules completely free. Ads are always optional: you can choose to watch a short video to double your rewards, unlock an element or get a hint in the library. If you are in the European Union you can choose whether to receive personalized ads or not, and manage your preferences at any time from the app's privacy options.