Orbital Order is a free browser Aufbau electron puzzle. Move the cursor to attract blue s-electrons and repel orange p-electrons, then seat them in empty orbitals. Fill six elements from hydrogen to oxygen. About ~32 KB after Play, no install, no account.
Want a radius-aim shooter instead? Try Orbital Radius Shooter. Prefer a space gravity mini-golf loop? Try Gravity Orbit Golf.
Cursor physics: blue electrons follow you, orange electrons flee. Seat them in orbitals without double-hitting filled shells. Keys: M mute, I help, L log, Esc close. Saves use ftol:orbitalorder:*. Adapted from aftongauntlett/js13k-demo (MIT). About ~32 KB.
Works best with a mouse or trackpad. On small phones a desktop hint may appear.
Welcome to Orbital Order - a free browser Aufbau electron puzzle with no account or install. Move the cursor to attract blue s-electrons and repel orange p-electrons, then guide each particle into an empty orbital without double-hitting a filled shell. Climb six elements from hydrogen through oxygen while procedural audio plays after the first click. About ~32 KB loads after you press Play. Best time and tutorial progress stay on-device under ftol:orbitalorder keys. Nothing is uploaded. For more free browser games, open the games hub. Related picks: Orbital Radius Shooter and Gravity Orbit Golf.
How the electron fill order works
The puzzle is built on the Aufbau principle: an electron settles into the lowest-energy orbital that still has room before any higher one begins to fill. That is why the inner 1s shell takes its two electrons first, then the 2s shell, and only then the roomier 2p shell. The blue s-electrons belong to those inner, earlier-filling shells, while the orange p-electrons belong to the outer shell that fills last - so seating them in that order is what keeps each atom building up cleanly as you climb toward oxygen.
| Fill order | Orbital | Electrons it holds |
|---|---|---|
| 1st | 1s | 2 |
| 2nd | 2s | 2 |
| 3rd | 2p | 6 |
Frequently Asked Questions
What is Orbital Order?
A free browser Aufbau electron puzzle. Guide electrons into atomic orbitals with cursor attract and repel physics.
How do I play?
Press Play, then move the cursor. Blue electrons follow you; orange electrons flee. Seat each electron in an empty orbital.
What happens if I hit a filled orbital?
Hitting an occupied orbital twice ejects the electron. Keep shells clean while you fill the Aufbau sequence.
What keys work?
M toggles mute. I or ? toggles help. L toggles the log. Esc closes the open panel.
Does it save progress?
Yes. Tutorial and fastest-time flags use ftol:orbitalorder:tutorialDone and ftol:orbitalorder:fastestTime in this browser.
How big is the download?
About ~32 KB of HTML, CSS, and JS after you press Play.
Is this open source?
Yes. Adapted from aftongauntlett/js13k-demo (MIT). Procedural Web Audio; no CDN assets.