I believe it's simply a chemist.
For example Antoine Lavoisier.
Jordan falconer
A chemist
The name of a scientist that studies sports is called a sports scientist.
A scientist who studies the changes of the states of matter is a scientist.
An arachnologist
A scientist who studies crystals is known as a Crystallographer.
A scientist who studies animals is called a zoologist.
A scientist who studies animal life is a zoologist. There is no particular name for a scientist that specialises in platypuses.
Wellrounded.
An archaeologist studies artifacts and remains from past cultures.
The name for this type of scientist is a teuthologist