Atom

Splashery stretches a drumhead over this Splash's outline, twelve inches across, and finds the ways it can ring. Its lowest is 1144.1 Hz, 46 cents flat of D6. The next fifteen are its overtones, and each one draws its own figure: sand gathers on the lines that stay still.

Tap it to speed up the electrons. Pick any of the 118 elements in the Splash tab.

Everything around you is made of atoms. Each one has a tiny heavy center, the nucleus, made of protons and (in almost every atom) neutrons, with electrons around it. The number of protons decides which element it is: carbon has 6, oxygen 8 and gold 79. Pick any of the 118 elements in the Splash tab.

This model draws the electrons in rings called shells, an idea of Niels Bohr's from 1913; pick the Cloud style for a truer picture, or Every nucleon to see all its protons and neutrons. Tap it and the electrons whirl faster until each shell blurs into a glowing ring, then slow down. The nucleus is tens of thousands of times smaller than the whole atom, which is mostly empty space.

This link opens it in the Playground. To put it on your own page, add the element and one script tag. Every option.