Answer:
Iridium becomes superconducting at extremely low temperatures, and its critical temperature (Tc) for superconductivity is approximately 0.11 Kelvin (K), or 0.11°C.
Step-by-step explanation:
Given that the critical temperature is given to two significant digits (0.11), your answer should also have two significant digits. Therefore, the temperature at which iridium becomes superconducting is approximately 0.11°C.