In actuality, this liquid is more often alcohol than mercury. Mercury is toxic, and so would be dangerous should the thermometer bulb break. Another advantage of alcohol is that the freezing ...

Tell students that this picture shows two thermometers that are identical in every way, except one has alcohol and the other has mercury inside. Point out that both thermometers are placed in hot ...

The thermometer has a small bulb filled with either mercury (in older thermometers) or alcohol (in modern ones). When the temperature rises, the liquid expands and moves up the narrow tube.