Question

why mercury is used in barometers?

Answer 1

bcz
1.It neither sticks nor get wets to the glass wall.
2.)It rises to a height 760 mm of Hg which is sufficient to balance the atmospheric pressure.
3.Itis opaque and shining .Hence it gives accurate reading.
4.It is easily obtained in free state.

Answer 2

Mercury is commonly used in barometers because its high density means the height of the column can be a reasonable size to measure atmospheric pressure. A barometer using water, for instance, would need to be 13.6 times taller than a mercury barometer to obtain the same pressure difference.