Question

Why did the water molecules that made up the ice absorb energy into them?

a) To decrease the temperature
b) To increase the temperature
c) To change from solid to liquid state
d) To change from liquid to solid state

Answer 1

Water molecules in ice absorb energy for the phase transition from solid to liquid, causing an increase in entropy but not in temperature during the melting process. After the ice has melted, further energy absorption increases the temperature of the water.

Step-by-step explanation:

The water molecules in the ice absorbed energy in order to change from a solid to a liquid state, which is option (c). When ice absorbs heat energy, the molecules begin to vibrate more vigorously, breaking down the hydrogen bonding that keeps them in a fixed position within the solid structure. This phase change occurs at the melting point without an increase in temperature, reflecting energy absorption used solely for changing the state rather than raising temperature. Once the ice has completely melted into water, any further absorption of heat will then raise the temperature of the liquid water.

During the phase transition from ice to water, the system's entropy increases as the molecules move from a highly ordered state (solid) to a less ordered state (liquid). Continued energy input beyond melting leads to further increases in entropy as water eventually reaches boiling and begins to transition into a gaseous state, characterized by even less order and higher entropy.