What actually happens when you chew on aluminum foil?

Question

i know i have done it before. but why does it give you that weird feeling? what is actually happening?

also, metals in microwaves. why does it spark when you accidentally leave a fork or spoon in there?

Answer 1

I had the same thing happen when I touched a fork to an amalgam filling in my teeth.  I asked my dentist about it and after he got over his intense heebee-jeebees ("Why on earth would you do that?") he said the sensation and the heat I felt in my tooth was a result of an ion exchange.  This was many many years ago and I don't remember all that he said, but I do remember that part.

Answer 2

I can answer the metal in microwaves part.  Metal is different than other materials because the electrons in metal atoms are held very loosely.  A metal is made out of a bunch of atoms who all share electrons a little bit, creating what my teacher called a "sea of electrons" because every individual atom is so electropositive that it doesn't hold on too tightly to its electrons.  The electrons float around between atoms like children raised in a commune with five different "mothers".  (weird analogy, but it works).  So when you put a piece of metal in the microwave, you are introducing energy to the system.  The electrons that were previously only semi-free floating now have enough energy to dance around, spark, and move.  They were already only loosely held by their electropositive atoms; now, in the microwave, they're sparking and dancing from one fork prong to another.  It takes energy to move through the air, and you've provided that energy.  It's cool to watch but you've got to be careful because you can break your microwave or start fires.  (energy out of control)

And I'm not sure what you mean by "chewing on aluminum foil".  I've never tried it, and can only imagine that it would hurt your teeth and wear the enamel off.  Why?  Does it spark when you chew it or something?