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If I were to use solid hydrogen (assuming temperature of 10K, pressure 1 atm) as a resistor of sorts, what would it's resistivity be?

(Note: If someone can give me a good resource on info like this for most of the elements, that would be very welcome).

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    $\begingroup$ There are different types of solid hydrogen. Metallic hydrogen is conductive. $\endgroup$ – Eugene Sh. Dec 19 '18 at 15:42
  • $\begingroup$ at 72 million psi it becomes metallic nytimes.com/2017/01/26/science/… $\endgroup$ – Tony Stewart Sunnyskyguy EE75 Dec 19 '18 at 15:43
  • $\begingroup$ Corrected. I do NOT mean metallic hydrogen, i just mean frozen hydrogen. $\endgroup$ – moonheart08 Dec 19 '18 at 15:44
  • $\begingroup$ I am not Chemistry expert (well, even not an amateur :) ) but this solid hydrogen is \$H_2\$, which (I think) is meaning that it has no free electrons, thus it will be an insulator. $\endgroup$ – Eugene Sh. Dec 19 '18 at 15:47
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    $\begingroup$ @KingDuken that is false, solid hydrogen gas been observed even back in the late 19th century. $\endgroup$ – KF Gauss Dec 20 '18 at 4:03
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Solid molecular hydrogen cooled below 14K at ambient pressure forms a hexagonal structure (hcp) and has a band gap of over 15eV. For comparison, teflon has a gap of 7.7eV and it has one of the highest resistivities known, $10^{25}$ Ohm-meter.

This means the pure solid molecular Hydrogen likely has a resistance that is orders of magnitude larger than teflon, and over 30 orders of magnitude higher than copper. I'm not sure if it would be measurable either.

Like any high resistance substance, measuring the actual resistance becomes extremely difficult due to other sources of conduction like defects, impurity phases, breakdown, etc. Added to the fact that solid hydrogen exists only at low temperatures, thermally activated carriers are highly suppressed. All in all, I don't think resistivity measurements are really practical in solid molecular hydrogen.

https://doi.org/10.1002/pssb.2220670133

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  • $\begingroup$ Not only is the band gap larger, but the density of the conducting electrons will also fall off rapidly with temperature. The density of conducting electrons generally contains a factor of $e^{-\Delta E/2 k T}$, where $\Delta E$ is the band gap. For a band gap of 15 eV and a temperature of 10 K, we have $\Delta E/2k T \approx 9000$; the same number is "only" about 150 for teflon at room temperature. $\endgroup$ – Michael Seifert Dec 19 '18 at 16:59
  • $\begingroup$ @MichaelSeifert that's right. Obviously a resistance of about ~$e^{-60}$ smaller than teflon is almost certainly not measurable, and likely other effects will dominate far before you would get such a resistance. $\endgroup$ – KF Gauss Dec 19 '18 at 17:41
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It seems it is also called Metallic hydrogen. An excerpt:

The researchers used a 1960s-era light-gas gun, originally employed in guided missile studies, to shoot an impactor plate into a sealed container containing a half-millimeter thick sample of liquid hydrogen. The liquid hydrogen was in contact with wires leading to a device measuring electrical resistance. The scientists found that, as pressure rose to 140 GPa (1,400,000 atm; 21,000,000 psi), the electronic energy band gap, a measure of electrical resistance, fell to almost zero. The band-gap of hydrogen in its uncompressed state is about 15 eV, making it an insulator but, as the pressure increases significantly, the band-gap gradually fell to 0.3 eV.

There are many lists, like:

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I am not sure metallic hydrogen has ever been produced (on the earth). It requires temperatures below 13.8K and enormous pressure (25GPa) or even more pressure at higher temperatures. Just solid hydrogen is not in a metallic state.


Edit: for non-metallic solid hydrogen, it's a pretty good insulator, one reference lists it at $$10^{19}\Omega-cm$$

That's called the "resistivity", and is a material property. The resistance depends on the geometry. For a constant cross-section of area A it's length/area multiplied by the resistivity, so resistivity has units of ohms * length.

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  • $\begingroup$ It is believed that metallic hydrogen can be found in large quantities in gas giants. $\endgroup$ – Eugene Sh. Dec 19 '18 at 15:44
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Jupiter and the other gas plant has a liquid metallic core that is conductive. To get the pressure needed, shock forces are used, meaning the right pressure (not to much and not to little) occurs for microseconds. But one of these test (never repeated), interesting indicted it was a superconductor. As a solid, the only thing I can find is that it does reflex light. It is said that hydrogen is the lightest element, but it's atom weight is greater than the average 1 amu. Both hydrogen and oxygen that makes water are in liquid form and held that way by a mysterious water bond. HHO generators (applying 1.4V or more to two plates is water breaks that bond and both become gases with an expansion of about 850:1 at 14.7 psi (1 atm), but in reality I calculated 1700:1 at 0 atm. Hydrogen is the best fuel by far at a gas. SEMPER FI

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The band gap of hydrogen is relatively high so you need lot of heat or lot of pressure for hydrogen to become conductive

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