Atomic Theory: The Historical Development of a Chemistry Concept

Democritus was the first to suggest that there was a particle that could not be divided any further. He coined the term "atomos" which we now refer to as atoms. Follow this link for a real-life example and why this term came to be.
https://www.youtube.com/watch?v=Xcc1qpTKC-Q

Aristotle was a well-respected scientist of his time. He disagreed with Democritus' ideas of the atom. Because of Aristotle's popularity, Democritus' ideas were banned. Check out this video to see a comparison of their thoughts. https://www.youtube.com/watch?v=C6LoleKOJQI

Over 2000 years after Aristotle, Dalton proposed Atomic Theory and it was finally broadly accepted. There are several parts to Atomic Theory that are explained in the video linked below. https://www.youtube.com/watch?v=kJ-6Qy05u_Q&t=110s

Almost 100 years later, another piece of vital information was discovered. Thomson determined that there were negatively charged particles that were smaller and lighter than atoms. He came up with a way of understanding the atom called the Plum Pudding Model. It sounds like a strange name, but the video below shows explains the meaning behind it. https://www.youtube.com/watch?v=RW_zfKOU9uM

Although Thomson is credited for discovering electrons, Rutherford proved his Plum Pudding model wrong. Rutherford is famous for the gold foil experiment. This experiment helped determine that most of the atom is empty space and the positive charges are compacted primarily in the center. Use the link below to dive into the differences between a Plum Pudding atom and a Rutherford atom. https://phet.colorado.edu/sims/html/rutherford-scattering/latest/rutherford-scattering_en.html

By the time Chadwick came along, we knew that there were positive particles and negative particles in an atom. He is responsible for the discovery of neutrons. Neutrons have the relatively the same mass as a proton, but no charge. Learn about his experiments by visiting the site below. https://www.youtube.com/watch?v=_7DAlvRI1M4