How the thermometer works

The thermometer is an instrument used to measure the temperature of a body or a place. It has been calibrated with marks with readings in (°C). The thermometer has mercury which is in a bulb at one end. When the thermometer is placed in a warm substance, the mercury in the bulb expands and rises up the stem of the thermometer. The new level gives the reading and that is given as the temperature of the substance. The unit of temperature is degree Celsius (°C).