The following passage has been extracted from the book "Modern's abc of Chemistry": Lets fill an isolated atom by subatomic "Rutherford projectiles"-alpha particles. I hope it is possible. This doesn't seem to be a limit of our technology. Isn't it? If we are successful in filling the an atom with alpha particles, we are decreasing the space for the electron and confining them to a least distance, isn't it? Doesn't this experiment, give us belief of measuring simultaneously both the position and momentum with little greater (or even complete) certainty than what predicted by Heisenberg's principle? This doesn't seem to allow us to fill an atom with alpha particles. So, can we fill an atom with alpha particles? The above question is also posted in Physics stack exchange, interested folks can visit: Can we "fill" an atom with alpha particles?