Respuesta :
I would say that it sounds like you are an alchemist as during the 1500's at least they tried to turn base metals like Pb or lead into Au or gold. While this is not possible, their experiments gave rise to the science and techniques of metallurgy and assaying as confirmed by the great first mine geologist, Georgius Agricola in the 1500's,
Since it says "I am best known for attempting to alter Pb#82 to AU#79" and "My goal is to achieve immortality", he is an alchemist.
If he has successfully converted Pb#82 to AU#79, then he is an experimental particle physicist as the conversion can only be done inside a particle collider.