Question

Why does Mercury have a convex meniscus?

Answer 1

The convex meniscus of mercury:

1. A surface boundary that is curved due to surface tension is called a meniscus.
2. A meniscus lens is a concave-convex lens where one of the faces is curved inward and another face is curved outward.
3. There are two types of meniscus lenses- concave and convex.
4. A convex meniscus is formed when the force of attraction is more between the particles compared to the walls of the container and a concave meniscus is formed when the force of attraction is less between the liquid molecules and due to this, they are attracted more towards the walls of the container.
5. Mercury forms a convex meniscus as there is a strong attractive force between the molecules of mercury than the force between the molecule and the walls of the container. On the other hand, water forms a concave meniscus.

The concave meniscus of water and convex meniscus of mercury are shown in the figure below.

Therefore, mercury forms a convex meniscus.