Pure silicon barely conducts — its four valence electrons lock into a flawless lattice with nothing left to carry current. A processor is what happens when you contaminate it on purpose: a few foreign atoms per million, placed with intent, turn an inert wafer into a billion switches.
1substrate
7dopants
9build materials
Si · the substrate
Substrate (valence 4)
Donor — n-type (valence 5)
Acceptor — p-type (valence 3)
Build material
outer glow = valence shell
Reading the cloud. Each atom is its electron probability density — dots cluster where the electron is most likely to be, sparse where it isn't. A denser shell means more electrons live there; the coloured outer glow is the valence shell that decides how the atom dopes. The cloud doesn't move — we slowly rotate the viewpoint to show its depth, and it shimmers to remind you these are probabilities, not fixed positions.