Physics Joke 1:
When a third grader was asked to cite Newton's first law, she said, "Bodies in motion remain in motion, and bodies at rest stay in bed unless their mothers call them to get up."

Physics Joke 2:
A neutron walked into a bar and asked, "How much for a drink?" The bartender replied, "For you, no charge."

Physics Joke 3:
Two atoms were walking across a road when one of them said, "I think I lost an electron!" "Really!" the other replied, "Are you sure?" "Yes, I 'm absolutely positive."

Chemistry Joke 1:
Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel:
Fe - Fe
/      
Fe       Fe
/
Fe - Fe

Chemistry Joke 2:
Q: What does a teary-eyed, joyful Santa say about chemistry?
A: HOH, HOH, HOH!

Chemistry Joke 3:
Q: What is the name of the molecule CH2O?
A: Seawater