Three children have been kidnapped for ransom. The prime suspect is their estranged father, a chemist who has become unhinged. Cryptic letters have been left with clues to the childrens whereabouts and it is up to you to solve the riddles.
![A picture of the kidnapping suspect from behind, speaking on the phone. Photo taken by Xinyu Cheng.](/pbl/sites/files/pbl/styles/full_width_m/public/shared/Crazy%20Scientist.jpg.webp?itok=J2L2pGIE)
Problem written by: Khoi Nguyen, Xinyu Cheng, and Dina Abu Baker
Curriculum items covered: Quantum numbers, periodic trends, Hund's rule.