In the late 1800s, J.J. Thomson built on earlier experiments using cathode ray tubes. The radiation emitted from the cathode (negative electrode) was accelerated toward the anode (positive electrode) in these tubes and was observed to be the same regardless of the composition of the cathode. The ray could be deflected away from the negative plate of an external electrical field and toward the positive plate. The ray could also be deflected by an external magnetic field, as would be expected for a negative particle. By controlling the strengths of the externally imposed electrical and magnetic fields, the two fields can be counterbalanced and the ray passes through the fields undeflected as when no fields at all were imposed. By knowing the strengths of these fields, it is possible to determine the charge-to-mass ratio of these cathode rays or particles.
Based on the data Thomson collected in his experiments using cathode rays, the concept of atomic structure was modified. Which of the following statements about the atomic structure were validated by his cathode ray experiments? Check all that apply.