The evolution of atomic theory covers our understanding of the atom and the nucleus and how it has changed over millennia. The first recorded theory of the atom was in the 5th century BC when Greek philosophers Leucippus and Democritus hypothesised that all matter was composed of small invisible particles called atoms. The ancient philosophers also went further to theorise that atoms came in a variety of shapes and sizes and could be hooked together to form different groups and different pieces of matter. From this they termed their work as atomists which in Ancient Greek translated as indivisible, based on their theory that atoms could not be cut into smaller pieces.
These theories were passed around for many hundreds of years in India, China and the Middle East being evolved but not really changed a lot. It was not until the 17th Century when a group of British scientists revived the ideas of atomists. These works were used by the scientist Rene Descartes in his theory of corpuscularism where he proposed that everything was made of tiny bits of matter which could be divided.
It was not util the 18th century that technological advancements and theories began to take shape that led to our modern day understanding of the atomic model with protons, neutrons and electrons.
Rene Descartes was a famous mathematician and philosopher of the 16th century who hypothesised the theory of corpuscularism about the atom
Corpuscularism was a theory proposed by Descartes that all matter was composed of tiny particles.
Atomists is the term given to the philosophers over time who believed in the theory and school of though the of the Ancient Greek philosophers Leucippus and Democritus
An atom is the smallest particle that makes up all matter
The nucleus is the term given to the centre of the atom comprising of the proton and neutron