Heating and Cooling Curves

At what temperature does water begin to melt, according to the heating curve?

• 100°C

• 0°C

• -10°C

• 50°C

What characteristic describes the temperature of a substance during a phase change, such as melting or boiling?

• It continuously increases.

• It continuously decreases.

• It remains constant.

• It fluctuates rapidly.

When a substance is in its solid state and its temperature is rising, what happens to its kinetic and potential energy?

• Kinetic energy increases, potential energy increases.

• Kinetic energy increases, potential energy remains constant.

• Kinetic energy remains constant, potential energy increases.

• Kinetic energy decreases, potential energy remains constant.

On a cooling curve, as a substance transitions from a gas to a liquid phase, how do its potential and kinetic energies change?

• Potential energy decreases, kinetic energy decreases.

• Potential energy increases, kinetic energy remains constant.

• Potential energy decreases, kinetic energy remains constant.

• Potential energy remains constant, kinetic energy decreases.