Shamelessly lifted from reddit:
What’s the integral of one over cabin?
Log cabin! (…plus C)
And since that one was so short, here’s another one:
A carbon-11 atom walks in to a bar, stares at the bartender for about 10 minutes, then orders a double whisky and instantly starts sobbing.
“What’s the problem, buddy?” the bartender asks as he delivers the drink.
The carbon-11 atom responds “I’m having a half-life crisis.”
Xanthippa's Chamberpot 