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THE CHEMISTRY LAB

Atom Builder.

Small particles. Big discoveries. Build an atom and see what changes.

A space to experiment.
A little chemistry, made visible.
Your level
Elements 1-20
A CLOSER LOOK
126C
Carbon-12
Neutral atom

Preparing your atom…

Drag to rotate · Scroll to zoomMODEL / SHELLS
ProtonNeutronElectron

Shells show energy levels, not electron paths. Model not to scale.

Atomic number Z66 protons
Mass number A126 protons + 6 neutrons
Net charge06 protons − 6 electrons
Meet carbon-12.

Six protons make this carbon. Try adding a neutron to explore another isotope.

MAKE IT YOURS

Build your atom

Loads a neutral atom of a common isotope.

Choose the element

Change the isotope

Change the charge

Electron arrangement

6 e⁻

Select a shell to take a closer look.

FOLLOW YOUR CURIOSITY

What happens if…

Understand this model

This is a simplified model, not to scale. Shell rings show electron energy levels, not paths that electrons follow. Particle sizes and distances are enlarged to make the structure clear.

Orbital views show schematic shapes and orientations. They are not calculated electron-density plots. A subshell can contain several orbitals; each orbital holds up to two electrons.

Particle counts can describe combinations that are not bound atoms or ions. This tool does not predict nuclear stability. Configurations are provided for neutral atoms and selected common ions; other combinations are marked as outside the configuration model.

Learn more: Royal Society of Chemistry periodic table ↗ · NIST isotope data ↗