What Makes Gold So Special?

The BBC series Bang Goes the Theory markets itself as sort of a shorter-form, British Mythbusters, but tends toward just answering simple questions or showing off science tricks (melting glass in a microwave, inflating a huge balloon in just one breath, etc). Here they look at why gold is used in electronics (like the presenter's cell phone) if it's so expensive (1000 per ounce according to the presenter).

I'm not entirely sold on the explanation that he gives - regarding simply the number of protons in the nucleus - because that would mean all large atoms would be non-reactive. I think there's something about gold's completely full d orbital, but explaining quantum mechanics and the electron orbital theory is probably a bit beyond the scope of the television programme (see, British spelling?).

It does, however, do a great job showing the kinds of things that we look at in materials science when we explore the activity series. Gold is very, very low on the activity series - down there with platinum and silver, all used for jewelry. Wonder if there's some reason for that...

Oh, I tried this experiment in class once. Dropped my gold wedding ring into concentrated hydrochloric acid and hoped. Turns out it worked just fine, but my wife wasn't too thrilled to hear about the experiment after the fact, so I don't do that anymore even though I'm pretty sure the science is solid.