Final answer:
Physical properties that change with temperature can be used to measure temperature, such as the volume of a liquid in mercury or alcohol thermometers, electrical resistance in RTD sensors and thermistors, and color changes in liquid crystals.
Step-by-step explanation:
Any physical property that changes consistently and reproducibly with temperature can be used to make thermometers. One common example is the volume of a liquid, which typically increases as temperature rises.
This expanding volume is the principle behind alcohol and mercury thermometers, where the liquid expands up a narrow tube as the temperature increases, providing a temperature reading.
Another physical property used is electrical resistance, which changes with temperature. This is the basis for resistance temperature detectors (RTD) and thermistors, which can measure temperatures with high accuracy and are used in various industrial and lab environments.
Additionally, the color change in materials, such as liquid crystals, can also indicate temperature changes as used in some simple, color-changing thermometers.
In summary, the volume expansion of a liquid is a common method to measure temperature, with its usefulness demonstrated in alcohol and mercury thermometers.Infrared thermometers work based on the emission of infrared radiation, which is another property that varies with temperature.