Author: [Poonamjeet Kaur] Intro duction At the turn of the 20th century, our understanding of the atom was drastically reshaped by a groundbreaking experiment conducted by Ernest Rutherford. Prior to this, J.J. Thomson’s "plum pudding model" was widely accepted. But Rutherford’s gold foil experiment in 1909 changed everything. The Gold Foil Experiment In his famous experiment, Rutherford directed a stream of alpha particles at a very thin sheet of gold foil. Most of the particles passed straight through, but a few were deflected at large angles, and some even bounced back. This unexpected outcome led to a new atomic model. Rutherford’s Atomic Model: Key Features 1. Nucleus at the Center: The atom has a small, dense, positively charged center called the nucleus. 2. Electrons Orbit the Nucleus: Electrons revolve around the nucleus in circular paths, much like planets around the sun. 3. Mostly Empty Space: Most of the atom's volume is empty, allowing alpha particles to pass ...