Scale: 10^-11 meters = 10 pm = 10 picometers

The Inner Electron Cloud

We have finally reached the two innermost electrons of the carbon atom. The quantum laws of atomic scale require a description of electron motion that is more subtle and less sequential than for the moving particles of ordinary experience. The maximum size for an electron, like that of the quark, is no more than 10^-18 meters (and possibly much smaller). Accordingly, the dot texture shown does not map individual electrons; instead, it suggests a cloud of electrical charge. Remember that the scale of the inner shell of two electrons that we see here is 1000 times larger than the nucleus – an invisible dot at the center of the image.