As part of an experiment in the science lab,a thermometer was inserted in a soultion in order to measure the temperature over time. At 9:15 a.m. the temperature was -17°C, and at 11:30 a.m. it was -26 °C. What is the difference between these two measurements? 8°C. 9°C. 11°C. 43° C.

The difference between the two measurements is 9°C.