Question

why is mercury often used in ordinary thermometer?

according to 7th class DAV
Science lesson-5 (heat)​

Answer 1

Answer:

because of its high melting point and fixed expansion rate

Answer 2

Answer:

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. It also has a high boiling point which makes it very suitable to measure higher temperatures.