Joke: Why did the mathematician name his dog "Cauchy?"

Joke: Knock knock!
Who's there?
Aldehyde!
Aldehyde who?
...
Must have been a leaving group.

Joke: Why is the tan function so quick to differentiate?

Joke: Tell me the symbol for Nobelium!
No.
Why?
Yttrium.
Oh!
Oxygen!

Joke: What do you get if you divide the circumference of a jack-o-lantern by its diameter?

Joke: What do you get if you eat Christmas decorations?