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? a. particles of the cathode rays are fundamental to all matter. b. in the atom, the particles of the cathode rays are embedded in a diffuse cloud of positive charge. c. matter contains negative charge and by inference positive charge. d. there are subatomic size particles in an atom. e. cathode rays have mass.

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?