Science jokes

When Magnesium and Oxygen started dating I was like, "O MG!"

Q: Why are Helium, Curium, and Barium the medical elements? 
A: Because if you can't heal-ium or cure-ium, you bury-um.

Q: How many engineers does it take to change a light bulb?

A: You need 250 just to lobby for the research grant.

A guy walking to library and asks for a book on sea turtles.
The librarian asks "hard back?"
The guy replies "yeah little heads too."