"4 d 10th time, guys! I'm not talking about a political party but the 46th element! Palladium!" :) Maybe? That's a hard one to do. Couldnt you do mercury? I have a wonderful joke for that one.
Why coudnt mercury hold still in class?
A. Because it was 80Hg! (get it? Say it vocally :) Sounds like ADHD right?)