Mercury has a low adhesive force to glass, it would rather bond to itself than another surface. This tends to create a spherical surface on open mercuric faces. Balanced by gravity the hemisphere flattens and creates the slight convex shape observed.
A meniscus is caused by surface tension and It curves down (concave) when the liquid adheres to the container more than to itself, like water and glass. Mercury clings more to itself than glass, so it is curved up (convex)
Surface tension
When we pour very hot water into an empty glass, the inner surface of the glass will expand as matter expands when heated. But the inner surface of the glass will expand more than the outer surface of the glass because more heat is applied to the inner surface of the glass.
When placed in boiling water, the materials comprising the thermometer respond in the order in which the heat penetrates them. As the heat first permeates the glass cylinder, the cylinder expands, enlarging the bore. For the moment until the mercury is also heated, the constant volume of mercury fills the expanded bore to a slightly lower depth. When the heat reaches the mercury and it also expands, its volume to increase, and the liquid depth rises in the bore.
Water has stronger adhesive forces than adhesive forses. Mercury on the other hand has stronger cohesive forces than adhesive. cohesive forces hold molecules of the same substance together , vice-versa for adhesive forces
The meniscus is the curve at a liquid's surface by which one measures the volume of the liquid. A meniscus can be concave or convex depending on whether it is attracted to itself or the glass.
The shape of the surface of a column of water actually depends on what the sides of the container are made of, but for a glass tube the surface is concave. This is because water likes to wet the glass. Some materials, such as teflon, water does not like to wet. On a teflon surface, water will form little beads and does not like to stick. A water column in a teflon tube would have a convex surface.This is because the wet glass has less surface energy than the dry glass. Since the universe always likes to reduce the total energy of a system, the water rises up the sides to make more wet surface and reduce the total energy. With a teflon surface, the dry surface has less energy and so the water is "repelled" from the surface.
The meniscus.Related Information:A meniscus can be concave or convex.For more information, see related links, below.
a water droplet and a magnifying glass
Mercury is a metal unlike water which have hydrogen bonding. Mercury does not wet most substances, because of its high cohesion and low adhesion to the glass mercury will not wet glass. Cohesion, along with adhesion(attraction between unlike molecules), can help explain mercury phenomena. Mercury has a surface energy over 6 times greater than that of water so there is a much greater attractive force between the atoms of mercury than between the molecules of water, so mercury does not wet glass.
Surface tension will attract the water solution to the molecules of the container thus lifting it up on the edges. Mercury, being much more dense has no such attraction because it is a liquid metal.Answer:It is due to what is called cohesion and adhesion. The water molecules are attracted to each other through cohesion, which is the attraction between similar particles (by polarity). Adhesion is attraction between unlike molecules. When water is placed in a glass container, the forces of adhesion overcome the forces of cohesion, and the water climbs up the glass. Conversely, the attraction between mercury atoms (cohesion) is stronger than its attraction to the glass (adhesion). Therefore, the atoms pull together and away from the glass.
mercury
The "wetting" that happens when an object is immersed in a liquid depends on the surface energy of the object and the capilary forces in action on the surface of the liquid. for example mercury will not "wet" glass but water can wet the same glass.
A meniscus is caused by surface tension and It curves down (concave) when the liquid adheres to the container more than to itself, like water and glass. Mercury clings more to itself than glass, so it is curved up (convex)
B/c the density of mercury is higher than that of glass, while the density of water is lower than that of water.
The force between glass and water are stronger than between water molecules
Glass