What is the surface tension of mercury at 20°C 

Explanation:

Surface Tension:

• Surface tension is the force acting per unit length on the surface of a liquid due to molecular cohesive forces.
• It is usually expressed in dynes per centimeter (dyn/cm) in the CGS system or in Newtons per meter (N/m) in the SI system.

The surface tension of a liquid is influenced by both temperature and the nature of the liquid. As temperature increases, surface tension typically decreases.

Surface Tension of Mercury:

• Mercury is a liquid metal with a very high surface tension due to its strong cohesive forces (metallic bonds) between mercury atoms.
• At 20°C, the surface tension of mercury is approximately 465 dynes per cm.
• This high surface tension is responsible for the nearly perfect spherical shape of mercury droplets.

Important Points

Mercury has one of the highest surface tensions among liquids, making it unique compared to other common liquids like water, which has a surface tension of about 72.8 dynes per cm at 20°C.

Additional Information

The high surface tension of mercury is primarily due to its strong metallic bonding, which results in the cohesion of mercury atoms, giving it properties like forming perfect spheres and higher resistance to deformation.