Currently, what superconducting material works with the highest temperature?

Well, the material that can work with the highest temperature currently is copper oxide!

I hope I helped in some way! :D

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.