Question

When boiling water in a kettle, the top may move slightly if it is not tight. What evidence explains why this happens? ​

Answer 1

Since the water is boiling, and a lid is on there is a major amount of thermal energy just waiting to go somewhere, not to mention it takes the form of steam which much escape somehow, likely causing a very faint movement on the top of the kettle.

Step-by-step explanation:

Answer 2

Usually, the hottest is at the bottom, if the kettle is on top of a heating ... Also, there's a factor that's not so important for kettles, but otherwise can be ... When a phase change (like liquid to gas) occurs, it normally begins at a location that ... a slight disturbance (like putting in a spoon or some sugar, or moving it ..

Step-by-step explanation: