Bradley "Rad" White is your typical kid who's the son of brilliant scientists. He likes to ride his bike, he likes to explore caves, he likes to grab excitedly at radioactive things—wait, what?

Basically, Rad has a natural, insatiable curiosity about all things. Unfortunately, this curiosity goes unchecked when he's hanging out with his best friend Carlos, so it takes the watchful eye of the intelligent-but-much-more-reserved Alexis to keep them both out of trouble. His parents hope that some day Rad can channel this curiosity more productively.

(Source: Transformers Wiki)