What is a Drop of Liquid Mercury?

Most metals or elements are always found in a solid state. Even though they can be melted and then reformed into something new, they are usually solid at room temperature. Well, in this case, we have an exception here which is mercury, which is why it is used in thermometers. There are no particular records about who discovered mercury. However, according to researchers, in the 4th century BC, Aristotle mentioned in his work about Hydro-Argyros, which means water silver or liquid silver. Well, today you will get to know what is a drop of liquid mercury and what is liquid mercury. How do you get liquid mercury? Let’s begin and find it out.

1. What is Mercury?

A heavy silvery and d-block chemical element known for its property of being liquid is mercury. It was earlier known as hydrargyrum, derived from the Greek words hydro means water, and Argyros means silver, therefore it is also known as quicksilver. Its modern chemical symbol is Hg and its atomic number is 80. To know what is a drop of liquid mercury, read till the end. (See What is Boron Made of?)

2. What are the Physical and Chemical Properties of Mercury?

This liquid metal has the following physical and chemical properties:

• Its atomic weight is 200.59.
• Its melting point is -38.89° Celsius.
• Its boiling point is 357.3° Celsius.
• The crystal structure of mercury is Rhombohedral.
• It has high surface tension.
• It has the tendency to wet other metals.
• It is the only metal that stays in liquid form at room temperature.
• Its droplets are silver-white and shiny.
• The droplets of mercury appear rounded from the edges when placed on a flat surface.
• It is not biodegradable.

3. What is Liquid Mercury?

The metal mercury in its liquid form is known as liquid mercury, elemental mercury, or metallic mercury. In this state, it develops an appearance similar to silver. Mercury is obtained in liquid form within the ore of cinnabar. Mercury is extracted from the ore through heating. Before moving ahead to know what is a drop of liquid mercury, understand liquid mercury and ways of obtaining liquid mercury in the next segments. (See What is the pH of Concentrated Nitric Acid?)

4. What are the Uses of Liquid Mercury?

This metal does not require large spaces as it has high density. Moreover, it is a good conductor of electricity, therefore it is used as a component in electrical switches. Some common things in which mercury is used in our day to life are as follows:

• Batteries
• Soaps
• Paints
• Thermometer
• Fluorescent Lamps
• Float Valves
• Liquid Mirror Telescope
• Dental Amalgams, fillings, and fittings
• Explosives
• Vaccines in form of thimerosal, a mercury-based compound
• Tattoo Ink
• Contact lens solution
• Cosmetics
• Vermilion
• Barometer
• Eye Drops

5. How do you get Liquid Mercury?

First, the ore of cinnabar is crushed and mercury is released as a vapor by heating. This vapor is then cooled down, condensed, and collected. Through this process, about 95% of the mercury is obtained from the cinnabar ore. What is a drop of liquid mercury is just around the corner, but before that understand the process. Various processes involved in extraction and obtaining liquid mercury are mentioned here:

a) Roasting

After the ore is mined out from the rocks, it is directly processed because the ore is concentrated and does not require waste removal steps. The ore is crushed into smaller pieces inside a crusher that rotates on an eccentric vertical axis inside a fixed outer core. In the mills, these pieces are further grounded and converted into fine powder. This powdered ore is heated in a kiln or furnace.

In this heating process, sulfur dioxide (SO2) is produced as the heated cinnabar (HgS) reacts with oxygen (O2) present in the air. As a result, mercury rises in the form of vapor. All this is known as roasting. 

b) Condensing

Along with the rising of mercury vapor, some fine dust of ore rises that needs to be separated and captured. The exhaust of the hot furnace passes through a condenser that is water-cooled, which cools down the vapor. The first element to cool down and condense is the mercury and other contents are left out to be removed or to be processed further.

The condensed mercury is in liquid form and gets collected in the container. Mercury has a high specific gravity which is higher than impurities in it. Thus, these impurities rise and form a dark film at the surface. After these impurities are removed, the remaining mercury is 99.9% pure.

c) Refining

The mercury obtained after the condensation process is pure and can be commercially used. However, higher purity of mercury can be attained after it is further refined. Several refining methods will mechanically filter the mercury in which impurities are removed through oxidation or by using chemicals. However, in some cases, an electric current is passed through a tank of mercury in the process of electrolysis.

Commonly, triple distillation is performed in which the temperature of mercury is carefully raised, leading to the removal of impurities each time. The purity of mercury increases after each distillation. (See What are Examples of Elements in Everyday Life?)

6. What is a Drop of Liquid Mercury?

It is the drop that is obtained through the process of dropping a mercury electrode. It is a working electrode made from mercury. Metals from this process are used in impedance measurements, voltammetry, and electrocapillarity. (See Which is Not an Example of Matter?)

7. How do you Obtain the Drop of Mercury?

An insulating capillary is used through which the mercury flows, producing a droplet as it exits from another end. The droplet grows in size from the end of the capillary until it reaches about 1 millimeter in diameter, after which it is released. Another drop follows the first drop of mercury and the process continues. These drops have a smooth surface and are free from any absorbed impurities. It is like a self-renewing electrode that does not require any polishing or cleaning.

So, today you got to know about what is a drop of liquid mercury. The answer to the question, what is liquid mercury, was hidden in the metal itself. Well, did you get the answer to how do you get liquid mercury? (See How many Electrons can a Carbon Atom share?)