Physical change of water in tea kettle: from liquid to gas, no chemical alteration.

Heating water in a tea kettle until steam is produced and the kettle whistles is an example of a **physical change**. Here's why: 1. **Change in State**: The water is simply changing its state from liquid to gas (steam). This is a physical change as the chemical composition of the water (H₂O) remains the same. 2. **Reversible Process**: This process is reversible. If the steam were to be cooled, it would condense back into liquid water. 3. **Whistling Sound**: The whistling sound is a result of the steam escaping through a small opening in the kettle, causing the air to vibrate. This is related to the physical movement of air and steam and not a chemical reaction. In summary, no new substances are formed during the process, and the molecular structure of the water doesn't change, indicating that it is a physical change.