(In the classroom, Claire has a name tag that says fluorine and is holding 7 balls, Amanda has a name tag that says lithium and is holding one ball)
Simon: So lithium, you can give your one valence electon to flourine.
(Amanda hands her ball to Claire and then pouts empty-handed)
Simon: And now they're both happy, because they each have... Lithium, you're BETTER OFF this way!
Simon: You still have a full shell, just like helium. Here you go.
(Simon hands Amanda two more balls, she looks enviously at the 8 balls Claire has)