Explore the Molecule Builder
Add atoms and see which real molecule you have built, with a 3D model and name. Free, no signup, runs in your browser.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
See it in action
The Molecule Builder with sample data entered and the result showing.
What is the Molecule Builder?
Add atoms and see which real molecule you have built, with a 3D model and name. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
Knowing how atoms combine is the foundation of drug design, materials science and understanding everyday substances.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
A molecular formula tells you how many atoms of each element are joined.
The same atoms can only make certain stable molecules.
Atoms are shown as balls and bonds as sticks.
Build water.
Build methane.
Try benzene.
Used for
Pick one to see how it fits.
Molecules learners
Chemistry and biology students learning bonding and molecular shape, and teachers who need an interactive 3D model instead of a textbook drawing.
Try it freeTeachers
For teachers: project the Molecule Builder on the board, let students predict the result, then run it together and test this: Build methane. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
What is a molecular formula?
A list of the elements in a molecule and how many atoms of each, such as H₂O for two hydrogens and one oxygen.
Why can't I make any combination of atoms?
Atoms form a fixed number of bonds (valence), so only certain combinations make stable molecules.
Is the Molecule Builder free to use?
Yes. The Molecule Builder is free, needs no signup or download and runs in your web browser. It is part of the Molecules group of AZRS simulations.
Does the Molecule Builder work on a phone or tablet?
Yes. The Molecule Builder takes touch input as well as mouse input, so you can use its 2 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Molecule Builder?
1. In the Molecule Builder, use the controls to change Try building, Element colours. The simulation reacts instantly. 2. In the Molecule Builder, press "Clear all" to start, reset or change what is happening. 3. Start with this experiment: Build water. Drag any glowing handle, object or slider with your mouse or finger and the Molecule Builder responds in real time. 4. Change one setting at a time and watch which readout moves, then compare it with this idea: A molecular formula tells you how many atoms of each element are joined.
More free tools
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Try the Molecule Builder now
Add atoms and see which real molecule you have built, with a 3D model and name. Free to use.
Try it free