I remember as a teenager how my Dad used electrons to explain facts and theories to me. We couldn’t see the actual functioning of the atom, but we used that theory because it explained the facts that we observed. This was an important and valuable lesson for me. While the definitions have stood the test of time, atoms have become much more observable. He might have needed something else to make the point.
New Atlas (citing researchers at Cornell University) is reporting a new imaging breakthrough that allows us to image atoms at an extremely high resolution. Nice to note that this new ability to collect facts doesn’t change the theory!