Robert Boyle was an English philosopher who is considered as the first chemist due to his experimental techniques who discovered the link between changing a gases pressure and its volume.
Alchemy is a term used to describe the historical study of elements and matter with the goal of creating an elixir for immortality or trying to change metals into more precious metals.
Alchemy whilst being the study of such wild theories as the transmutation of metals and prolonging of life also had many useful origins of chemistry today from drug design to experimental techniques we still use in the lab today.
The modern Atomic Model was first developed by two key scientists Lavoisier and Dalton with the help of others. They formulated the key concepts of the law of conservation of mass and the existence of atoms as the building blocks of all matter using their knowledge of chemical reactions.