Super Effective Teaching Method

(I’m in college prep chemistry. The teacher is doing flame test demonstrations of various elements. With most of them, he’s told us beforehand what element he was using, but with this one, he doesn’t. He simply puts the wire with the element solution in the bunsen burner flame, then drops the wire, collapses on the floor and groans.)

Classmate: “Oh, my god! Is he okay?”

(The teacher laughs, although you can tell he’s trying not to, then keeps moaning. I go up and look at the label on the jar he had used, and chuckle.)

Me: “We should have known, guys. It’s krypton.”