Final answer:
Melting is the physical process where ice becomes water when heat is applied, causing water molecules to break their fixed positions without changing the composition of the substance. The temperature remains constant at 0°C during this state change, and only the physical state of water alters.
Step-by-step explanation:
The process in which ice becomes water is known as melting, which is a physical change. This occurs when heat is transferred to the ice, causing the water molecules within the ice to vibrate and absorb kinetic energy. As the temperature rises to 0°C, the hydrogen bonds that hold the water molecules in a fixed position begin to break apart. The ice changes state from solid to liquid without a change in temperature during this phase change, as all the heat energy is consumed in the melting process. Similarly, if heat is removed from water at its freezing point, it will undergo the reverse process of freezing, transforming back into ice and releasing the heat of fusion. To provide an example, when you hold an ice cube in your hand, heat from your hand is transferred to the ice, resulting in it melting. This heat transfer is the same reason why your hand feels cold as the ice melts. Melting ice demonstrates that the physical appearance of water can change, but its composition remains consistent, comprising 11.19% hydrogen and 88.81% oxygen by mass regardless of its state being solid or liquid.