Question about: conductivity: gold, silver, copper, and aluminum.

05 Jun.,2025

 

Question about: conductivity: gold, silver, copper, and aluminum.

Good evening everyone,

On Mike’s quizzes under the theory this question arose.

Reference: Unit 9 - Electrical Formulas - 9.3 Conductance

The best conductors, in order of their conductivity, are: gold, silver, copper, and aluminum.

The correct answer is False.

I thought this would be true.

Please help me understand.

Thanks for your time, Silver is #1

Conductivity refers to the ability of a material to transmit energy. There are different types of conductivity, including electrical, thermal, and acoustical conductivity. The most electrically conductive element is silver, followed by copper and gold. Silver also has the highest thermal conductivity of any element and the highest light reflectance. Although it is the best conductor, copper and gold are used more often in electrical applications because copper is less expensive and gold has a much higher corrosion resistance. Because silver tarnishes, it is less desirable for high frequencies because the exterior surface becomes less conductive.


As to why silver is the best conductor, the answer is that its electrons are freer to move than those of the other elements. This has to do with its valence and crystal structure.
We gold plate contact surfaces not because of the high conductivity of gold, but because of its resistance to corrosion. This is particularly important when switching low voltages which cannot break down a thin insulating layer.
Thanks for your reply, have a great weekend! -231 EDT

Gold should plated over nickel because gold is pourus, and nickel is not. If you use gold only, then you probably want gold thicker than at least 50 millionths.

Gold contacts for low voltage signal circuits are a great advantage at little cost.

However, there are some environments where gold is even a problem. Here a reed switch may be a better choice.

. So the answer commonly given is conductivity per volume (yes I know that is the definition). What about by mass? It's actually difficult to find information on that (yes I could do the math, but too lazy).
We gold plate contact surfaces not because of the high conductivity of gold, but because of its resistance to corrosion. This is particularly important when switching low voltages which cannot break down a thin insulating layer.
Thank you sir.
So the answer commonly given is conductivity per volume (yes I know that is the definition). What about by mass? It's actually difficult to find information on that (yes I could do the math, but too lazy).
Thanks
-231 EDT

Gold should plated over nickel because gold is pourus, and nickel is not. If you use gold only, then you probably want gold thicker than at least 50 millionths.

Gold contacts for low voltage signal circuits are a great advantage at little cost.

However, there are some environments where gold is even a problem. Here a reed switch may be a better choice.

.
Thanks “reed switch” don’t understand.
So the answer commonly given is conductivity per volume (yes I know that is the definition). What about by mass? It's actually difficult to find information on that (yes I could do the math, but too lazy).
Aluminum win the conductivity/weight contest We often silver plate RF feed elements because in the real world everything oxidizes. Turns out that Silver oxide has about 90% of the conductivity of Silver. Copper oxide is has about 50% the conductivity of Copper. This is a big deal in the RF world because of skin effect.

Nickel is a great plating intermediary, but it is too lossy for RF.

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