materials
I have always had it in my head that gold plated contacts were preferred.
I noticed today that the resistivity is as follows:
Silver 1.5×10-8
Gold 2.4×10-8
Is there another property that makes gold preferable to silver for use in electrical contacts?
The usual method of lightning protection is to convince the lightning strike to follow a less harmful path than through the item being protected. Hence, lightning rods and lightning arrestors.
Ohm's law resistivity assumes linear behavior- this is not what happens when you have enormous voltages and currents at play. Air is supposed to be a pretty good insulator, but lightning reaches through it. Many meters of air. A thin bit of polyethylene film is an almost perfect insulator, but a few thousand volts will punch a hole through it. At high current it will carbonize and become a pretty good conductor. A lightning strike is hundreds of thousands of volts and tens of thousands of amperes typically.
That said, there may be information available on what ground conditions are like. Geophysical surveys looking for natural resources sometimes use EM methods to find ground conductivity such as this map of Electromagnetic Ground Conductivity. It will vary greatly depending on what is under the ground.
It depends on the kind of touchscreen it is. At this point, I think most technology is based on capacitance, and not multi-layer resistance. If this is the case, you might want to look into how those touch-screen capable gloves work. These are gloves that have a finger and a thumb covered in some material that works with modern touchscreens.
There is also apocryphal evidence that a hotdog, cold out of the fridge, works on these screens. Make of that what you will.
Best Answer
Gold doesn't oxidize, which means that gold-to-gold contact has no extra resistance.
In other words, it isn't about the bulk resistance (the plating is very thin anyway), but about the contact resistance.
Silver is used in places where the resistance to current flow along a surface matters, such as the interior of a waveguide or the outside surface of a high-power RF coil. In these applications, a layer of oxidation doesn't affect performance.
Silver is also frequently used on larger RF connectors, where gold would be too expensive and not durable enough. The mechanical sliding of the contacts and threads when assembled is enough to break through any oxidation.