The property of matter illustrated by boiling water in a kettle is change of state.

Here's why:

* Water starts as a liquid.

* Heat energy is added by the kettle's heating element.

* The water molecules gain energy and move faster.

* At a specific temperature (100°C or 212°F), the water molecules have enough energy to break free from their liquid bonds and transition into a gaseous state. This is what we see as steam.

So, boiling water demonstrates how matter can change from one state (liquid) to another (gas) through the addition of heat.