Barium.
HeHe
Son: I couldn't find a spider.
Lithium and Iron
The element of some fries.
One, but you can be sure a whole Reddit community will appear to expand the joke, make it funnier and eventually run it into the ground.
Hippocampus!
Because if you can't Helium or Curium, you Barium. (Heard it from Heimerdinger, League of Legends)
You Barium.