An Explosion Of Thought(less)

(I am a junior, and I am sitting in an upper-level chemistry class just as the teacher is about to give us a test. Another chemistry teacher walks in from the supply room between the two chemistry classes carrying a five gallon-or-so bottle like the ones use on top of water coolers. The bottle appears to be empty.)

Teacher #2: “Mrs. [Teacher #1], do you have a match?”

Teacher #1: “Of course.” *puts down quizzes and retrieves matches from her desk*

Teacher #2: *lights match and drops in bottle, then smiles gleefully as the explosion rocks the entire room*

Teacher #1: *laughs*

Teacher #2: “Yup, I was right. That was methane.” *turns and walks out the door like nothing happened*