RE: 2 1/2 the diameter of a single silver atom.
A. That is precisely my point Tony. A silver ion is approximately 0.33nm in dia. which is much smaller than 2 -1/2 times the size of an atom. And so here again, the point is that there is no way for a silver particle(elemental) to be either; equal-to, or smaller than silver ions, as this would imply subatomic particles, of which I'm of the opinion that you are not in favor of - see: ionic silver solutions
1. The diameter of a single silver ion is 0.33nm
2. The diameter of an average silver particle is approximately 15nm, or, 45x larger than an ion.
In short, a silver ion is one single atom, whereas metal nanoparticle are made-up of several silver atoms clustered together. And so, the discrepancy with your interpretation is where a silver ion is essentially the same size(dia.) as a silver atom, and that it would be impossible to create anything smaller than an ion this side of the physical world. And perhaps more to the point, where it it would logically impossible to conclude that ionic silver cannot be beaten on particle size, otherwise, it would not be ionic(see).