Main article: Atomism
The idea that matter is made up of discrete units is a very old one,
appearing in many ancient cultures such as Greece and India. The word
"atom", in fact, was coined by ancient Greek philosophers. However,
these ideas were founded in philosophical and theological reasoning
rather than evidence and experimentation. As a result, their views on
what atoms look like and how they behave were very incorrect. They also
couldn't convince everybody, so atomism was but one of a number of
competing theories on the nature of matter. It wasn't until the 19th
century that the idea was embraced and refined by scientists, when the
blossoming science of chemistry produced discoveries that only the
concept of atoms could explain.First evidence-based theory
