History of Atomic Theory & Scientists
Ever wonder what makes up everything around you? Scientists have been trying to figure this out for over 2,000 years! It all started with Democritus, a Greek philosopher who coined the term "atomos" (meaning "indivisible") around 400 BCE. He believed matter could only be divided so many times before reaching an indivisible unit.
John Dalton took this idea further in 1803 with his Billiard Ball Model, proposing atoms were indestructible and elements had unique atomic masses. Then came a game-changer: J.J. Thompson discovered electrons in 1897 using cathode ray experiments, leading to his Plum Pudding Model where negative electrons were embedded in a positive sphere.
The atomic model dramatically changed when Ernest Rutherford conducted his famous Gold Foil Experiment in 1911. When alpha particles bounced back instead of passing through gold foil, he realized atoms must have a dense, positively-charged nucleus. Neil Bohr refined this in 1913 with his Planetary Model, suggesting electrons orbit the nucleus at fixed distances.
Did you know? The modern atomic model we use today comes from Erwin Schrödinger (1926), who described electrons as both particles and waves existing in a probability cloud rather than fixed orbits!
Our understanding of atoms has evolved from simple indivisible particles to complex systems with protons, neutrons, and electrons behaving in fascinating ways that follow quantum mechanics principles.
