Models of the Atom
The atom's structure has been a mystery scientists have worked to solve for centuries. Each model built upon previous discoveries, creating a more accurate picture of what atoms truly look like.
Dalton's Solid Sphere Model (1803) portrayed atoms as simple, indivisible spheres combining in fixed ratios. This basic model drew inspiration from ancient philosophers like Democritus. J.J. Thomson revolutionized this concept in 1904 with his Plum Pudding Model, suggesting atoms had a positive outer layer with negative particles inside, based on his Cathode Ray Tube experiments.
Rutherford's Nuclear Model (1911) made a groundbreaking discovery through his Gold Foil Experiment. He found that atoms were mostly empty space with a dense, positively charged nucleus at the center. Bohr expanded on this in 1913 with his Bohr Model, proposing electrons orbit in fixed energy levels around the nucleus, explaining atomic emission spectra.
Remember This! Modern atomic theory uses the Quantum Model (1926) developed by Heisenberg and Schrödinger, which describes electrons moving in "probability clouds" called orbitals rather than fixed paths.
