ok these ain't exact pick up lines, but just some random chem jks:
atom A looks very miserable
atom B: "hey dude, wut happened?!"
atom A: "i lost an electron..."
atom B: "are you sure?!"
atom A: " yeh i am positive... "
this one thx to daniella fort of 03, and resent to all fort of 03 via email:
a neutron went to a bar...
neutron: "hey, how much's a serve of scotch cost?"
bartender: "for you?! free of charge..."