What properties explain the behavior of liquid-filled thermometers?

Liquids expand upon heating and contract upon cooling.

thanks.. What are the two reference temperature on the Celsius Scale?

Freezing point of water is 0o C and boiling point is 100o C. I suppose they may serve as reference points.

Correct! The freezing point and boiling point of water are two important reference temperatures on the Celsius scale.

To explain how to find these reference temperatures, you can use the Celsius scale as a guideline. The Celsius scale divides the range between the freezing and boiling points of water into 100 equal parts, each called a degree Celsius (°C).

To find the freezing point of water, you simply look for the temperature where water transitions from a liquid to a solid state. This occurs at 0°C.

Similarly, to find the boiling point of water, you look for the temperature where water transitions from a liquid to a gaseous state. This occurs at 100°C.

These two reference points are crucial in everyday thermometry and serve as a baseline for many temperature measurements.

Yes, you are correct. The freezing point of water at 0°C and the boiling point of water at 100°C are the two reference temperatures on the Celsius scale. These specific points provide a consistent and easily reproducible reference for temperature measurements.