Are the superconductivity properties "all or nothing"? Meaning, if you get the synthesis wrong of the material, would you expect it to be "kind of" superconductive? (I guess, a very low, but non-0, resistance)?
Or is it something where it has normal resistance in all cases unless you get it just right, and then it becomes superconducting?
One more question - in physics, it seems like something having a value "0" is never really possible. Like, you can have something with low friction, but not zero friction. We pretend things have zero friction for high school physics problems, but they don't really. Is superconductivity like that? Is it actually, genuinely, exactly 0.0000(...)? Or is it just very close to zero, so close that it can behave like something with zero resistance (but in reality it's resistive, but just barely)?