Question

If mercury is a bad conductor of heat, then why is it used in thermometer and how does it show the temperature ?​

Answer 1

Answer: Most metals are good conductors of heat and they are solids at room temperature. Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it's used in a thermometer.