Question

A teacher demonstrates an experiment to a class. A boiling tube is filled with water and some ice cubes are trapped at the bottom of the tube. The teacher then heats the boiling tube in the position shown until the water at the top boils.
The ice does not melt.
What does this demonstrate?

• A. Water is a good conductor of thermal energy
• B. Water is a good convector of thermal energy
• C. Water is a poor conductor of thermal energy
• D. Water is a poor convector of thermal energy

Answer 1

The correct option is C Water is a poor conductor of thermal energy

Water has a very large heat capacity, so it takes a lot of energy to change the temperature. Warmer water will be less dense and move upward to the top of the test tube to boil while the colder water can stay at the bottom. Water does not conduct heat through it very much and ice conducts the heat through much less.