The question comes along these answer choices:
A. lower than the mercury in the vessel, and shaped like the outside of an umbrella.
B. higher than the mercury in the vessel, and shaped like the outside of an umbrella.
C. lower than the mercury in the vessel, and shaped like the inside of a bowl.
D. higher than the mercury in the vessel, and shaped like the inside of a bowl.
Answer: option A. lower than the mercury in the vessel, and shaped like the outside of an umbrella.
Step-by-step explanation:
That is what is called convex meniscus and is due to the high cohesion forces of mercury.
There are two opposing forces that take place in the formation of the meniscus: the cohesion, which is the attraction of the liquid mercury atoms among each other, and the adhesion, which is the attraction of mercury atoms to the molecules on the glass tube's walls (polar molecules of the glass tube).
Since, in mercury the cohesive forces (between the mercury atoms) are stronger than the adhesive forces (between mercury atoms and the glass tube's molecules), the cohesion overcomes the adhesion, meaining that the atoms try to remain together and, therefore, form the convex meniscus. Since the glass tube is upside down, the surface of the mercury inside of tube will be lower than the mercury in the vessel, and shaped like the outside of an umbrella.