Which of the following observations indicates that an atom has neutrons?
a. Some uncharged particles are scattered by a beryllium atom when it hits a gold foil.
b. Some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles.
c. Radiation with neutral particles is emitted
when alpha particles strike beryllium atoms.
d. Radiation which attracts eiectrons is produced when a beryllium atom is bombarded with alpha particles.
