Build a molecule, then spin it around.
Pick a molecule or drag atoms together to form your own bond. Drag anywhere to rotate, scroll to zoom, and hover an electron pair to see what's being shared.
Everything responds to a click or a drag.
No menus to dig through — the whole model is the interface.
Pick a starting molecule
Choose from H₂, O₂, N₂, H₂O, CO₂, CH₄, NH₃ and more. The model rebuilds instantly with correct bond angles and electron counts.
Drag to rotate in 3D
Click and drag anywhere on the stage to spin the molecule. Scroll or use the + / − buttons to zoom into the bonding region.
Adjust bond and lone pairs
Use the steppers to change the number of shared pairs and lone pairs, then watch the geometry and bond angle update live.
Hover to identify
Hover any electron pair or bond to see whether it's a bonding pair, a lone pair, or a polarised shared pair — and where it sits.
What you're actually looking at.
The model is drawn to make three real chemical facts easy to see, not just decorative motion.
Shared electron pairs
The thick glowing line between two atoms represents a shared pair of electrons. One line = 2 electrons shared. Two lines = 4 electrons. Three lines = 6 electrons.
Lone pairs
Electrons that don't participate in bonding appear as paired dots around the atom. Water has two lone pairs on oxygen; ammonia has one; methane has none.
Bond angle & geometry
The angle shown is the real experimental value. Lone pairs push bonding pairs closer together — that's why water's angle is smaller than methane's perfect tetrahedron.
Questions people actually ask.
The short answers — with the long ones one tap away.
What is a covalent bond?+
A covalent bond is a chemical bond formed when two atoms share one or more pairs of electrons. Each atom contributes at least one electron to the shared pair, and the shared electrons are attracted to both nuclei simultaneously, holding the atoms together.
How is a covalent bond different from an ionic bond?+
In a covalent bond, atoms share electrons, while in an ionic bond one atom transfers electrons to another, creating charged ions that attract each other. Covalent bonds typically form between nonmetals, while ionic bonds form between metals and nonmetals.
What is a Lewis structure and how do I read one?+
A Lewis structure shows valence electrons as dots around element symbols, with shared pairs drawn as lines between atoms. Bonds are lines, lone pairs are dot pairs, and the structure must satisfy the octet rule for most atoms. Counting all dots and lines gives the total valence electrons in the molecule.
What determines the shape of a molecule?+
Molecular shape is determined by VSEPR theory — electron pairs around a central atom repel each other and arrange themselves as far apart as possible. Lone pairs repel more strongly than bonding pairs, which is why water is bent rather than linear.
What is a polar covalent bond?+
A polar covalent bond forms when electrons are shared unequally because the two atoms have different electronegativities. The more electronegative atom pulls the shared electrons closer, giving it a partial negative charge (δ−) and leaving the other atom with a partial positive charge (δ+).
Can atoms share more than one pair of electrons?+
Yes. Sharing one pair forms a single bond, two pairs form a double bond, and three pairs form a triple bond. Multiple bonds are shorter and stronger than single bonds between the same two atoms. Nitrogen gas (N≡N) has a triple bond; oxygen gas (O=O) has a double bond.
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.