jan 1, 1911 - Ernest Rutherford Atomic Theory
In 1911, Ernest Rutherford proposed that the atom consisted of a small, dense core of positively charged particles in the center of the atom, surrounded by a swirling ring of electrons. The nucleus was so dense that the alpha particles would bounce off of it. This was concluded after the gold foil experiment and it proved the "Plum Pudding Model" wrong.
Added to timeline:
Atomic Theory Timeline - Adrianne Moran 4th Period Chemistry