Question

why the metal mercury used in thermometer ​

Answer 1

Answer:

this is because mercury is in liquid state at room temperature

Answer 2

Answer:

mercury is the only one in the 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. it also has high boiling point which makes it very suitable to measure higher temperatures.