[amelius]

I mean, the actual interaction force that defines "touching" is open for debate. Touching is an abstract concept, removed from actual physics.

[z2h-a6n]

That was sort of my point. If we use a definition of "touching" that is relevant to the atomic scale, whatever that definition is, we can reasonably talk about what "touching" means at an atomic scale. If we use a colloquial definition of "touching" which is meaningful for macroscopic objects but not at the atomic scale, it doesn't make sense to talk about "touching" at the atomic scale.