Introduction

An atom is just the smallest unit into which any substance can be decomposed or broken down into whilst still retaining its chemical properties. The term was originated in ancient Greek philosophy where it was used to describe the smallest bit of metal, the smallest piece of matter that could be conceived of. By the early scientific revolution in the 17th and 18th centuries most scientists did believe in the concept of atoms though at this stage there was little empirical support for the idea. Empirical support for the atom will not come until the 19th century and I will talk about that momentarily.