Tap one atom then another to join them · tap a stick or spring to take it out · drag atoms to move them
Pick a molecule to build, then take atoms out of the kit.
Build this
The kit
Tap a ball to take one out of the box. The number of holes is what limits how many bonds it can make.
How is it going
How to use this simulation
Pick a molecule to build from the Build this list. It shows the formula and how many atoms you'll need.
Tap a ball in The kit to take an atom out onto the workspace. Each atom has a fixed number of holes — that limits how many bonds it can make.
Choose stick (single bond) or spring (double bond) from the tools, then tap one atom and then another to join them. Tap a connector to remove it, and drag atoms to move them.
Watch the readouts at the top: Building, You have, Open holes, and Built update as you work.
Press Check my model to see whether your formula, connectivity, and open holes all match — the How is it going panel tracks all three live.
Press Give me a clue if you're stuck, or Back in the box to clear the workspace and start over.