thermometer

A thermometer is a device used to measure temperature. It contains a liquid that expands or contracts when it is heated or cooled.

The liquid in a thermometer is usually mercury or alcohol. Mercury is a silver-coloured liquid that is very sensitive to changes in temperature. Alcohol is a clear liquid that is also sensitive to changes in temperature.

The thermometer has a scale that shows the different temperatures. The scale is usually divided into degrees Celsius or degrees Fahrenheit.

To use a thermometer, you put the end of the thermometer in the object whose temperature you want to measure. Then, you wait for the liquid to stop moving. The temperature of the object is the temperature that the liquid is at.

The doctor used a thermometer to measure my temperature.