Question

When a solid such as ice begins to melt, heat energy is added. What is the function of this added heat energy?

a. to increase potential energy
b. to separate hydrogen atoms from oxygen atoms
c. to break the bonds between the individual water molecules
d. to add energy to the hydrogen bonds among water molecules

Answer 1

to break the bonds between the individual water molecules

Answer 2

The function of the heat energy added is to c. to break the bonds between the individual water molecules. This is because solid water molecules are more tightly packed together. Heat energy is needed to melt the ice and disperse its molecule arrangement into that of liquids which are less packed together.