Question

In the picture of the water in the pot above, there are some changes happening to the liquid. What are they? List three changes that are occurring. Be sure to use science terminology that includes matter and thermal energy. For example, the water in its liquid state is boiling.

Answer 1

When water is heated in a pot, the temperature rises until it reaches the boiling point, at which point it undergoes boiling, a phase change from liquid to gas. This change does not alter the molecular structure but changes the state of the water due to increased thermal energy.

Step-by-step explanation:

When water in a pot is heated, it undergoes visible changes indicating a change of state due to the input of thermal energy. Here are three changes happening to the water:

1. Temperature Increase: Initially as heat is applied, the thermal energy increases the water's temperature until it reaches its boiling point of 100° C.
2. Boiling: Once at boiling point, the water undergoes a phase change from liquid to gas, also known as vaporization. During this process, additional heat energy doesn't increase the water's temperature but facilitates the change of state.
3. Vaporization: As the water boils, vaporization occurs at the surface as well as throughout the liquid ('bubbles'), where water molecules escape as steam into the air, a demonstration of a physical change where matter changes from liquid to gas.

These changes exemplify the effects of added heat to water, resulting in a change of state from liquid to gas while maintaining its molecular structure (H₂O). The observed changes such as boiling and vaporization are part of the dynamic processes that occur when energy is transferred to water.