Want to stay on top of all the space news? Follow @universetoday on TwitterThe Democritus model is the earliest atomic model of which there is written evidence. Democritus, the author of this model, lived from 460 BC to 370 BC. He was an ancient philosopher that spent more of his time wandering into the realm of science than actually espousing philosophy. He was the first to use the term atom and proposed that atoms were mechanically bound. It seemed to him that if atoms stayed together they did it with a system like a hook and eye. While we know that this is not true, he was very far ahead of his time by acknowledging the existence of the atom and many people consider him the father of modern science for his contributions.
His model of the atom depended on analogies from human senses. Using these analogies, he gave a picture of an atom that distinguished one from another by their shape, size, and the arrangement of their parts. In addition, these connections were explained by material links in which single atoms were supplied with attachments: some with hooks and eyes others with balls and sockets and were inert. These mechanical attachments were how atoms bound to each other. In contrast, modern, quantum-mechanical atoms interact via electric and magnetic force fields and are far from inert. He also reasoned that the solidness of the material corresponded to the shape of the atoms involved. Iron atoms are solid and strong with hooks that lock them into a solid; water atoms are smooth and slippery; salt atoms, because of their taste, are sharp and pointed; and air atoms are light and whirling.
Many of his teachings and beliefs are mired in the writings of his teacher, Leucippus. And that makes it hard to separate who wrote what. Democritus and Leucippus were referred to as atomists in their day. They face a lot of criticism for the theory. Aristole was a very vocal opponent. He criticized the atomists for not providing an account for the cause of the original motion of atoms. The theory of the atomists appears to be more nearly that of modern science than any other theory of antiquity. The problem was that their theories had no real empirical basis, so their belief was devoid of any solid foundation. The atomists were seeking plausible explanations for the world, and can be viewed as having hit on a hypothesis that it took another two thousand years to find some evidence to support.
This is a link to an article about Democritus. Here on Universe Today we have two great articles that are related to the topic at hand. One is about the Democritus model and the other is about the most widely accepted atomic model, the Bohr atomic model.