-ray in shooting through an atom is able to remove from that atom more than one single electron at a time.
The foregoing result has been obtained by shooting the
-rays from polonium through a rarefied gas in an oil-drop apparatus of the type sketched in [Fig. 12], catching upon a balanced oil drop the positively charged residue of one of the atoms thus ionized, and counting, by the change in speed imparted to the droplet, the number of electrons which were detached from the captured atom by the passage of the
-ray through or near it.[66]
This mode of experimenting extended to helium, however, has yielded the most interesting result[67] that every sixth one on the average of all the passages, or “shots,” which detached any electrons at all from the helium atom detached both of the two electrons which the neutral helium atom possesses. Since some of the ionization produced along the path of an
-ray is probably due to slow-speed secondary