Science Week Joke-Day 8 & International Year of Chemistry Joke

For your delight and pleasure we have a double header today... two jokes for the price of one! The First is for the final day of Science Week :(
Q: What is the fastest way to determine the sex of a chromosome?
A: Pull down its genes.
Second is for the International Year of Chemistry

Two atoms are walking down the street.

Says one atom to the other, "Hey! I think I lost an electron!"

The other says, "Are you sure??"

"Yes, I'm positive!"