We can see electrons.

Or, well, their valences, which is as good as it gets without Heisenberg getting in the way. Yeah, the Corante Pipeline has a post describing what it’s like to look inside atoms:

The researchers have improved the resolution and sensitivity, narrowing things down to single-atom tips. So instead of a tungsten surface, we have a single carbon atom at the end of a chain. And instead of the behavior of the electrons in a bulk metal, we have the electron density around one nucleus. Behold the s and p orbitals. Generations of students have learned these as abstractions, diagrams on a page.