julio checked the temperature of a bag of frozen peas and found it was at −13°c. after he left the bag out of the freezer for an hour, its temperature rose to 8°c. what was the change in temperature in an hour?
a)−21°c
b)21°c
c)5°c
d)−5°c

The change is the difference final temperature less initial temperature.

ΔT = final temperature - initial temperature = 8°C - ( -13°C) = 8°C + 13°C = 21 °C.

So, the temperature raised 21 °C, and that is the change in temperature.

change = option b) 21°C.