Why mercury is used in thermometer?

Mercury is used in thermometers eventhough its a bad conductor of heat due to its really high sensitivity towards heat,mercury expands significantly even for a small rise in temperature for which other metals show no or relatively smaller change . read more

Mercury has a higher coefficient of expansion than water, which means that changes in its volume with temperature are more noticeable. read more

One special kind of mercury-in-glass thermometer, called a maximum thermometer, works by having a constriction in the neck close to the bulb. As the temperature rises, the mercury is pushed up through the constriction by the force of expansion. read more