For example Antoine Lavoisier.
Jordan falconer
I believe it's simply a chemist.
A chemist
The name of a scientist that studies sports is called a sports scientist.
A virologist is a scientist who studies viruses.
An arachnologist
A scientist who studies animals is called a zoologist.
A person who studies physics is called a physicist, a person who studies chemistry is called a chemist, and a person who studies biology is called a biologist.
A scientist who studies radioactivity is called a nuclear physicist or a radiologist.
A scientist who studies animal life is a zoologist. There is no particular name for a scientist that specialises in platypuses.
The name for this type of scientist is a teuthologist
This answer is a entomologistA scientist who only studies fish is called an ichthyologist.