I shot the sheriff

Two hydrogen atoms walk into a bar. One says, "I think I've lost an electron."
The other says, "Are you sure?"
The first says, "Yes, I'm positive..."

So, a neutron walks into a bar. "I'd like a beer" he says. The bartender promptly serves up a beer. "How much will that be?" asks the neutron.
"For you?" replies the bartender, "no charge."

An electron walks into a bar and sighs to his friend: "I'll never get a date". His friend replys: "it's because you tested positive"