The evolution of atomic models has been a fascinating journey marked by key discoveries that have shaped our understanding of the fundamental building blocks of matter.
Dalton's atomic theory in the early 19th century proposed indivisible atoms as the basic units of elements. J.J. Thomson's cathode ray experiments in the late 19th century led to the discovery of electrons, challenging Dalton's indivisibility concept. Rutherford's gold foil experiment in 1909 revealed a small, dense nucleus at an atom's center, with electrons orbiting around it.
Bohr further refined the model, introducing quantized electron orbits. Quantum mechanics, developed in the early 20th century, replaced Bohr's orbits with probability distributions, and the current understanding incorporates wave-particle duality. These successive discoveries have paved the way for the sophisticated atomic models that underpin modern physics and chemistry.