There have been several reiterations of the Firestorm character over the years (his most recent transformation under the new 52 storyline.), however I wish to focus on the original hero that was created by Gerry Conway and Al Milgrom. This was the Firestorm known as the “nuclear man” and was created by the merging of two individuals:
Ronnie Raymond and Martin Stein.
The origin story of Firestorm was that a nuclear accident merged high school student Ronnie Raymond with Nobel Prize-winning physicist Martin Stein. Ronnie Raymond retained control of the merged form, and Professor Stein would serve as the voice of logic and guide to Ronnie. There is alot of banter between the two characters as they form a somewhat symbiotic relationship.
Firestorm’s super powers was the ability to rearrange the molecular or particle structures of any substance. That is he could transmute one object into another. For example, he had the ability to change lead into gold. This power could only work on inorganic items and NOT organic matter. In addition, Firestorm had the ability to phase his molecules between substances as well as fly at supersonic speeds.
The Firestorm character first appeared in Firestorm the Nuclear Man #1 (March 1978). The first series was short-lived, abruptly canceled with issue #5 (this was due to the DC company-wide cutback aka the DC Implosion).