What is Atomic Theory?
Atomic theory is the idea that matter is made up of little units called atoms. When the ancient Greek philosopher Democritus came up with the idea in the 5th century BC, is was originally meant to refer to indivisible units. As of 1897, the British scientist J.J. Thomson discovered that atoms are in fact made up of smaller particles. Today atomic theory refers to matter being made up of units that are indivisible only some of the time. Exceptions include plasmas such as fire, other ionic arrangements such as those found in the body, radioactive materials, and many more. Even though atomic theory today is a familiar cornerstone of modern science, like germ theory or evolution, throughout most of human history people believed that matter was probably continuous and could be broken down into arbitrarily small quantities. It wasn’t until 1803, or possibly a bit before, that the English chemist John Dalton revived the old idea of atomic theory, and used it to solve various problems that che
