Molecule Lab

Molecules aren't flat. Their three-dimensional shape decides almost everything — whether they dissolve, how they smell, whether they fit a receptor in your body. Grab a molecule, spin it, and see the shape for yourself.

Why shapes happen: VSEPR

Valence-Shell Electron-Pair Repulsion sounds fierce but says something simple: the pairs of electrons around a central atom all repel each other, so they spread out as far apart as they can get in 3D. That single rule predicts the shape of almost any small molecule:

2 groups → linear (CO₂, 180°)
3 groups → trigonal planar (BF₃, 120°)
4 groups → tetrahedral (CH₄, 109.5°)
a hidden lone pair bends things: water (104.5°) and ammonia (107°) are squeezed from the ideal angles

Shape decides polarity

Turn on Show polarity. A bond is polar when one atom pulls the shared electrons harder — but the molecule is only polar if those pulls don't cancel. CO₂ has two polar bonds pointing opposite ways, so it cancels to non-polar. Water's two bonds point the same general way, so they add up — and that's why water is such a good solvent, why ice floats, and why life works.

Try the Real molecules row — caffeine, aspirin, glucose. These are the exact structures chemists measured, rendered from public-domain data. Same shapes your body actually meets.

3D coordinates from PubChem (U.S. National Institutes of Health, public domain). Three highly symmetric shapes (BF₃, PCl₅, SF₆), marked ✷, use idealized VSEPR geometry. Rendering and explanations by SpecEnvoy. Nothing here is tracked.

Part of SpecEnvoy Chemistry — build the atoms first in the Atom Builder, or combine them in the Equation Balancer.