Question

a heating curve shows how the _ (y - axis) changes as a substance is heated up at a constant rate over _ (x - axis).

Explanation:

A heating curve is a graphical representation. In such a curve, the y - axis typically represents the temperature of the substance. As the substance is heated (inputting heat energy), the temperature changes. The x - axis represents time because the heating is done at a constant rate over a period of time.

Answer:

Temperature; Time