A kid takes a chemistry test, but in order to pass the class he has to get a perfect score on the test. He studied hard, but when he gets it back he got one question wrong. The question was "How many valence electrons does hydrogen have?" In a rush, he had answered, "Two".
Depressed, he walks home. But as he is walking he kicks a random lamp. He picks up the lamp and suddenly a genie flies out of it and says, "In return for releasing me from the lamp, I will grant you one wish!"
The kid replies, "I wish got that question right," and the universe explodes.