Q: Why was the mole of oxygen molecules excited when he walked out of the singles bar? A: He got Avogadro's number! 2158 5
As an ion chromatography chemist I made this one up: Anions aren't negative, they're just misunderstood. 2028 1
Helium walks into a bar. The bartender says "We don't serve noble gasses in here." Helium doesn't react. 2259 1