Build a molecule, then spin it around.
Pick a geometry or adjust bonding pairs and lone pairs. Drag anywhere on the model to rotate it, scroll or pinch to zoom, and hover a particle to see what it is.
Everything responds to a click or a drag.
No menus to dig through — the whole model is the interface.
Pick a geometry preset
Choose a shape from the dropdown or click a tile in the mini grid — the model rebuilds itself instantly with the right angles and positions.
Spin and zoom the model
Click and drag anywhere on the stage to rotate the molecule in 3D, and use the + / − buttons or your scroll wheel to zoom into the central atom.
Adjust bonds and lone pairs
Use the bonding pair and lone pair steppers to morph the shape and watch the geometry name, bond angles and hybridization update live.
Hover to identify a particle
Hover any bonded atom or lone pair to see exactly what it is and where it sits in the structure.
What you're actually looking at.
The model is drawn to make three real chemical facts easy to see, not just decorative motion.
The central atom
The atom in the middle is where all the action happens. Its bonding pairs and lone pairs determine the entire shape of the molecule through VSEPR repulsion.
Lone pairs
Lone pairs are shown as fuzzy clouds because they occupy more space than bonding pairs. They squeeze bond angles smaller — which is why water is 104.5° instead of 109.5°.
Bond angles
The angle between bonded atoms is determined purely by how many electron domains surround the central atom. The readout panel shows the ideal angle for each geometry.
Questions people actually ask.
The short answers — with the long ones one tap away.
What is VSEPR theory?+
VSEPR stands for Valence Shell Electron Pair Repulsion. It states that electron pairs around a central atom arrange themselves as far apart as possible to minimize repulsion. This determines the electron-pair geometry, and the molecular geometry is what you get after accounting for lone pairs.
How do lone pairs affect molecular shape?+
Lone pairs occupy more space than bonding pairs because they are held by only one nucleus. This extra repulsion pushes bonding pairs closer together, reducing bond angles. For example, methane (CH₄) has 109.5° angles, but ammonia (NH₃) with one lone pair has 107°, and water (H₂O) with two lone pairs has 104.5°.
What are the main molecular geometries?+
The main geometries based on electron domains are: linear (2 domains), trigonal planar (3), tetrahedral (4), trigonal bipyramidal (5), and octahedral (6). When lone pairs are present, the molecular shape changes to bent, trigonal pyramidal, seesaw, T-shaped, or square pyramidal.
How do you determine hybridization?+
Hybridization is determined by the number of electron domains around the central atom: 2 domains = sp, 3 = sp², 4 = sp³, 5 = sp³d, and 6 = sp³d². This explains the geometry and bond angles observed in the molecule.
What is the difference between electron geometry and molecular geometry?+
Electron geometry includes all electron domains (bonding pairs and lone pairs) around the central atom. Molecular geometry describes only the positions of the atoms, ignoring lone pairs. For example, water has tetrahedral electron geometry but bent molecular geometry.
Why are bond angles important?+
Bond angles determine the 3D shape of a molecule, which in turn affects its physical properties, reactivity, and how it interacts with other molecules. Small changes in bond angles can dramatically change a molecule's behavior, especially in biological systems like enzymes and receptors.
Is this tool free, and where does my data go?+
It's completely free and runs entirely in your browser — nothing you build or click is uploaded, logged, or sent to any server. No account, no sign-up, no limits.