SCIENCE: MATTER AND TEMPERATURE.
EXPLAIN WHY THE POTENTIAL ENERGY INCREASE WHEN ICE STARTS TO MELT AND BECOMES LIQUID WATER.
When ice starts to melt and becomes liquid water, the potential energy increases due to a change in the molecular arrangement and bonding within the substance.
In solid ice, the water molecules are arranged in a rigid and organized lattice structure held together by hydrogen bonds. Each molecule is surrounded and connected to neighboring molecules, creating a stable and ordered network. The molecules have limited freedom of movement, vibrating in fixed positions.
When heat is added to the ice, the molecular motion increases, supplying energy to the system. As the temperature rises, the kinetic energy of the water molecules becomes sufficient to overcome the forces holding them together. The hydrogen bonds start to break, and the molecules gain mobility, resulting in a phase change from a solid to a liquid.
During this phase transition, the potential energy of the system increases. The bonds between water molecules need to be broken, requiring energy input. Breaking the hydrogen bonds between molecules requires work to overcome the electrostatic forces that hold them together. This work done against the attractive forces contributes to the increased potential energy.
Additionally, as the ice melts and the water molecules gain mobility, the spacing between the molecules becomes greater, increasing their potential energy. In the solid state, the molecules are closely packed in an ordered manner, while in the liquid state, they have more freedom to move and occupy a greater volume. The increased spacing between molecules corresponds to an increase in potential energy.
Overall, the potential energy increases when ice melts and becomes liquid water because of the energy required to break the hydrogen bonds between water molecules and the increased spacing between the molecules when transitioning from a solid to a liquid state.