Answer to Question #176233 in Physics for Katie

Question

Which of the following statements correctly describes the energy of water molecules when they are being changed from the solid state to the liquid state at 0 oC?

(a) The internal energy stays the same.

(b) Their kinetic energy is increasing.

(c) Their internal energy falls.

(d) Their kinetic energy stays the same.

Answer 1

At the melting point, the heat added is used to break the attractive intermolecular forces of the solid instead of increasing kinetic energy, and therefore the temperature remains constant. 

Answer: (d) Their kinetic energy stays the same.