The semester final for Mr. Garcia's science class required students to design and conduct an investigation that would answer the question "Is
styrofoam a better insulator than plastic?"
Which experiment would be most effective in helping students obtain evidence to use in answering this question?
100 mL of 70 °C water placed in 200 mL plastic cup
O A. 100 mL of 10 °C water placed in 250 mL plastic cup
wait 20 minutes, remeasure temperatures
50 mL of 70 °C water placed in 250 mL styrofoam cup
OB. 100 mL of 70 °C water placed in 250 mL plastic cup
wait 20 minutes, remeasure temperatures
100 mL of 70 °C water placed in 200 mL plastic cup
OC. 100 mL of 70°C water placed in 200 mL styrofoam cup
wait 20 minutes, remeasure temperatures
100 mL of 70°C water placed in 250 mL styrofoam cup
OD. 100 mL of 20 °C water placed in 200 mL styrofoam cup
wait 20 minutes, remeasure temperatures
100 mL of 70 °C water placed in 200 mL plastic cup
O E. 100 mL of 70 °C water placed in 250 mL styrofoam cup
wait 20 minutes, remeasure temperatures

The correct answer is C because it puts equivalent measurements in the equivalent cup size. Both cups in answer C are the same measurement: 200 mL. The water in both cups is also the same measurement: 100 mL of 70 degrees Celsius. This is important because equivalent measurements for everything mean the experiment will be fair, equal, and accurate. If the measurements were not equal to each other, your experiment would not be as accurate.