How to play
- Choose a set: Single bonds, Double bonds or Triple bonds.
- Read the target at the top, for example Water (H₂O). The counters show how many atoms of each element you have and how many you need.
- Pick an atom from the tray. The first atom goes in the middle. After that, click a glowing open bond on the molecule to attach the atom you are holding.
- Click a bond to make it double, and again to make it triple. Both atoms need a free bond for that. One more click sets it back to single.
- The molecule is complete when it has exactly the right atoms and every atom has used all of its bonds. It then spins so you can see its shape, and its lone pairs appear as yellow lobes.
Each molecule is worth 100 points when it is built in the fewest possible steps. Every extra step, including Undo and Clear, takes 10 points off (down to 40), and a hint halves the points. Score 85% or more in a set for three stars.
What students learn
Every atom in the game shows its open bonds as glowing spots, so students see at once how many bonds it can still make. That number comes from the element’s valence:
| Element | Bonds it makes | Lone pairs (in these molecules) |
|---|---|---|
| Hydrogen (H) | 1 | 0 |
| Oxygen (O) | 2 | 2 |
| Nitrogen (N) | 3 | 1 |
| Carbon (C) | 4 | 0 |
A double bond uses two of an atom’s bonds and a triple bond uses three. That is why oxygen gas needs a double bond and nitrogen gas a triple one. The shape then follows VSEPR theory: bonds and lone pairs around an atom (its electron groups) push each other as far apart as possible. Two groups make a straight line, three make a flat triangle and four make a tetrahedron. A double or triple bond counts as one group.
The 11 molecules
| Molecule | Formula | Bonds | Shape | Real bond angle |
|---|---|---|---|---|
| Water | H₂O | 2 single; 2 lone pairs on O | Bent | 104.5° |
| Ammonia | NH₃ | 3 single; 1 lone pair on N | Trigonal pyramidal | 107° |
| Methane | CH₄ | 4 single | Tetrahedral | 109.5° |
| Methanol | CH₃OH | 5 single | Tetrahedral carbon, bent C–O–H | about 109° |
| Oxygen gas | O₂ | 1 double | Linear | 180° |
| Carbon dioxide | CO₂ | 2 double | Linear | 180° |
| Ethene | C₂H₄ | 1 double, 4 single | Trigonal planar around each carbon | about 120° |
| Formaldehyde | CH₂O | 1 double, 2 single | Trigonal planar | about 120° |
| Nitrogen gas | N₂ | 1 triple | Linear | 180° |
| Hydrogen cyanide | HCN | 1 triple, 1 single | Linear | 180° |
| Ethyne (acetylene) | C₂H₂ | 1 triple, 2 single | Linear | 180° |
A note on accuracy. The game spreads electron groups evenly, so the angles on screen are the ideal ones: 109.5° for four groups, 120° for three and 180° for two. In real molecules a lone pair pushes a little harder than a bond, which squeezes the angle to about 107° in ammonia and about 104.5° in water. The card that appears after each molecule gives the real value, which makes a good discussion point. Atom sizes and bond lengths are not to scale.
Works on the devices you already have
| Device | How to look around | How to pick |
|---|---|---|
| Chromebook or laptop | Drag with the mouse, or use the arrow keys | Click an atom or bond. Keys H, C, N and O pick atoms from the tray, Space clicks what is in the centre and Ctrl+Z undoes. |
| Phone or tablet | Drag with a finger, or tap Motion and move the device | Tap an atom, an open bond or a bond |
| Cardboard-style viewer | Tap Cardboard, then put the phone in the viewer | Keep looking at the target for about a second and a half |
| VR headset (Meta Quest and other WebXR browsers) | Tap Enter VR and look around naturally | Point with a controller and pull the trigger |
A 25-minute lesson plan
- Warm-up (5 minutes). Write H₂O and CO₂ on the board. Both have three atoms. Ask students to predict which one is straight and which one is bent, and why.
- Build (12 minutes). In pairs, students play the Single bonds set and then the Double bonds set. Before each molecule is finished, the partner who is not building predicts its shape.
- Discuss (5 minutes). What decides the shape: the number of atoms, or the number of electron groups around the central atom? Compare water with carbon dioxide and ammonia with formaldehyde.
- Exit ticket (3 minutes). Students draw the Lewis structure of one molecule they built and name its shape.
Fast finishers can play the Triple bonds set and explain why nitrogen gas, which makes up about 78% of the air, hardly reacts with anything.
Comfort, safety and privacy
- Players stay in one spot, so there is no artificial movement to cause motion sickness.
- Sit or stand still with clear space around anyone wearing a headset, and take a break every 10 to 15 minutes.
- There are no accounts and no personal data. Best scores are saved only in the browser on the device being used.
Frequently asked questions
Do students need a VR headset?
No. The game works on any laptop, Chromebook, tablet or phone with an up-to-date browser. Cardboard viewers and VR headsets are optional.
Why does water look like it has a 109.5° angle?
The game places all four electron groups around oxygen evenly, which gives the ideal tetrahedral angle. Real water is a little narrower (104.5°) because its two lone pairs repel more strongly than its two bonds. Ask students to explain the difference: it is a classic exam question.
Can students build other molecules?
They can build freely, and the game tells them when every atom is full. Only the target molecule completes a level, though, so the score always matches the task.
Does it work on school Chromebooks?
Yes. It runs in Chrome with nothing to install. If the 3D scene does not appear, check that “Use graphics acceleration when available” is turned on in Chrome’s settings.
Is it free?
Yes. The game and this guide are free for classroom and home use.
More free tools: All games · VR Field Trip · Science & Math Simulations · Growth Mindset Game · AI Literacy Game