1. Solid Sphere Model: Proposed by John Dalton in the early 1800s, this model depicted atoms as tiny, indivisible spheres.
2. Planetary Model: Developed by Ernest Rutherford in 1911, this model pictured the atom as a positively charged nucleus with negatively charged electrons orbiting around it like planets around the sun.
3. Quantum Mechanical Model: This model, developed in the 1920s by physicists like Erwin Schrödinger and Werner Heisenberg, is the most accurate description of the atom we have today. It uses complex mathematical equations to describe the probability of finding electrons in certain regions of space, rather than defining specific orbits.
