Atomize THAT!

My younger 12 years old brother has build a working stink bomb this week. My mother, concerned, searched his files on the PC and found out that he has downloaded a description how to build an atom bomb (and even translated it from english to german, he, who is so bad at english as she says...). She completely freaked out, but he just said to her yelling at him: Mom, calm down! I don't have Plutonium anyway.