Not to scale

This atom

Mass number

Charge

Isotope

Nucleus

Electron shells

In the real world

Periodic table Tap one to build it

Your molecule

Atoms0

Bonds0

Open0

Models to explore

Molecules you made

Controls

Name this element hides the labels, builds a mystery atom and asks the class to count the protons.

Appearance

Text size

Contrast

Animation

Reduced animation slows the electrons, stops the spinning and skips the confetti.

Keys: 1 to 4 switch modes. In Atom, P, N and E add a proton, neutron or electron, and Shift with the same key removes one. In Molecule, H, C, N and O add an atom, U undoes and Delete removes the selected atom. V changes the view, T labels, Q challenges, G name this element, X empties, F present, M controls, R reset, D light or dark, A text size, Esc closes.