Atomic-Man is a fictional superhero created by Charles Voight who first appeared in Headline Comics #16-21 (1945). He is also the first atomic superhero.
Origin story
Dr. Adam Mann was experimenting with uranium-235 after the first atomic bomb was used. During the experiment he suffered a side effect from the uranium changing him into the superhuman being known as the Atomic-Man. His superpowers include "Atomic Blasts", flight, invulnerability, and super strength.
References
Atomic-Man Wikipedia(Text) CC BY-SA