Chapter 17, Problem 6RQ

To determine

Which process requires the removal of heat: melting or freezing.

Answer to Problem 6RQ

The freezing requires the removal of heat.

Explanation of Solution

The transformations of matter are of two types. The types are physical change and chemical change. The physical change includes the change of states of matter.

There are three states of matter. The states are solid, liquid, and gas. The different states are due to the difference in the movement of molecules that are present in matter.

The states change when the heat is applied or removed.

In melting, the phase changes from solid to liquid. It happens when the heat is supplied. When the heat is supplied, the particles in the solid vibrate more violently. After enough heat is supplied, the intermolecular forces of attraction are not able to hold the particles together.

In freezing, the phase changes from liquid to solid. It happens when the heat is removed. when the heat is removed, the particles move slowly and the intermolecular forces between them become strong and particles come closer.

Conclusion:

Therefore, the freezing requires the removal of heat.