A maximum thermometer and a minimum thermometer differ in that they use, respectively:

1. Each thermometer is filled with the liquid best suited to the extreme it records. 2. A maximum thermometer uses mercury, which has a high boiling point and so survives high temperatures. 3. A minimum thermometer uses alcohol, which stays liquid at temperatures where mercury would freeze. 4. That lets the alcohol register very low readings that mercury could not reach. 5. The two liquids are chosen for opposite reasons, so swapping them round makes each thermometer useless for its purpose. _Source: NECTA CSEE 2021 Physics 031, Question 1: Multiple Choice, item (v)_