Correct option is D
Rutherford's
alpha particle scattering experiment, conducted in 1911, was crucial in the discovery of the
atomic nucleus. In this experiment, Rutherford and his team directed a beam of alpha particles at a thin gold foil and observed the scattering patterns. While most particles passed through the foil, a few were deflected at large angles, and some even bounced back. This unexpected result led to the conclusion that most of the atom's mass is concentrated in a very small, dense, positively charged region at the center of the atom, which Rutherford called the
nucleus.
Before this experiment, the widely accepted model was J.J. Thomson's "plum pudding model," which suggested that the atom was a diffuse cloud of positive charge with electrons scattered throughout. Rutherford's findings showed that the atom consists of a small, dense nucleus surrounded by a cloud of electrons, fundamentally changing our understanding of atomic structure.
