Janet learned in science class that the amount of salt that can dissolve in a certain amount of water depends on the temperature
of the water. She decides to do an experiment to test this. She carefully adds salt, 100 mg at a time, to a cup of water and stirs until all the salt dissolves. When she has added so much salt that it will not dissolve after 5 minutes, she measures the temperature of the water. She records the temperature and the final amount of salt. She does this with cold water, cool water, room-temperature water, warm water, and hot water. What is the independent variable in this experiment?
A. the temperature of the water
B. the amount of salt
C. the amount of water
D. how long it took the salt to dissolve
