Home / Chemical Elements / Mercury

Mercury

Table Of Contents

What is Mercury
Isotopes
Where is Mercury Found
History
Mercury Identification
Properties and Characteristics of Mercury
Atomic Data of Mercury (Element 80)
What is It Used for
Its Toxicity and Health Effects
Interesting Facts
Cost of Mercury

What is Mercury

Mercury (pronunciation: MER-kyoo-ree) is a heavy, silvery element belonging to the family of transition metals in the periodic table and represented by the chemical symbol Hg ^{[1, 2, 3]}. It is the only metal that exists in its liquid form at standard temperature and pressure conditions ^[4].

Mercury Symbol

Isotopes

Mercury is characterized by seven stable isotopes out of which ²⁰²Hg occurs most with a natural abundance of 29.86% ^[5]. There are about 34 radioactive isotopes of mercury with ¹⁹⁴Hg and ²⁰³Hg being the longest-lived having half-life periods of 444 years and 46.612 days respectively ^[5].

Where is Mercury Found

It is mostly found combined with other elements in nature but can occur as tiny droplets in cinnabar, which are red mineral ores of mercury (II) sulfide ^[1]. The element is extracted by heating the mineral ore in the presence of air and then condensing the vapor ^[1]. China, Kyrgyzstan, and Chile are the top mercury-producing countries while Mexico, China, and Kyrgyzstan have the highest mercury reserves in the world ^[1].

History

Origin of its Name: It is named after ‘Mercury’, the fastest planet in the solar system to revolve around the Sun while its chemical symbol is derived from ‘hydrargyrum’, Greek for “liquid silver” ^{[2, 6]}

Who discovered it: The element was probably discovered thousands of years ago and used by the ancient people in India, China, and Egypt, as it has been found in trace amounts in the 3500-year-old Egyptian tombs ^[2].

When and How was it Discovered

The early humans used cinnabar (mercury sulfide) to decorate the caves in France and Spain with paintings during the Paleolithic era about 30,000 years ago ^[1]. The metal was widely used by the ancient people as a liquid to extract gold from the sediment of rivers ^[1]. As a liquid, the mercury would dissolve gold that could be recovered through distillation of mercury ^[1].

The Spanish conquerors in the Americas obtained cinnabar from the mercury deposits at Huancavelica in Peru to extract gold ^[1]. It was also used by the miners to obtain gold from the New Almaden Mines during the California Gold Rush in 1848 ^[1]. Mercury was also used by several chemists, including Carl Wilhelm Scheele, Joseph Priestley, and Humphry Davy to discover other elements ^[7].

Mercury Symbol

Mercury Identification
Atomic number	80 ^[1]
CAS number	7439-97-6 ^[1]
Position in the periodic table	Group	Period	Block
	12 ^[1]	6 ^[1]	d ^[1]

Where is Mercury on the Periodic Table

Properties and Characteristics of Mercury

General Properties

Relative atomic mass

200.592 ^[1]

Atomic mass

200.592 amu ^[1]

Molar mass

200.5900 g/mol ^[8]

Molecular weight

200.592 g/mol ^[4]

Mass number

201 ^[9]

Physical Properties

Color

Silvery-white ^{[1, 7]}

Melting point/freezing point

-38.829 °C, -37.892 °F ^[1]

Boiling point

356.619 °C, 673.914 °F ^[1]

Density

13.5336 g cm^-3 ^[1]

State of matter at room temperature (solid/liquid/gas)

Liquid ^{[1, 7]}

Thermal (heat) conductivity

8.3 W/(m K) ^[10]

Specific heat

140 J kg^-1 K^-1 ^[1]

Bulk modulus

25 GPa ^[1]

Shear modulus

Unknown ^[1]

Young’s modulus

Unknown ^[1]

Vapor pressure

– Temperature (K)

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

– Pressure (Pa)

140

–

Chemical Properties

Oxidation state/Oxidation number

+1,+2, (+4) ^[1]

Isotopes

Isotope

Mass

Abundance (%)

Half-life

Mode of decay

¹⁹⁶Hg

195.966

0.15

> 2.5 X 10¹⁸ y

¹⁹⁸Hg

197.967

9.97

–

¹⁹⁹Hg

198.968

16.87

–

²⁰⁰Hg

199.968

23.1

–

²⁰¹Hg

200.970

13.18

–

²⁰²Hg

201.971

29.86

–

²⁰⁴Hg

203.973

6.87

–

Atomic Data of Mercury (Element 80)

Valence electrons	2 ^{[1, 11]}
Quantum numbers
– n	5 ^[12]
– ℓ	2 ^[12]
– m_ℓ	2 ^[12]
– m_s	-1/2 ^[12]
Electron configuration (noble gas configuration)	[Xe] 4f¹⁴5d¹⁰6s² ^[1]
Atomic structure
– Number of electrons	80 ^[9]
– Number of neutrons	121 ^[9]
– Number of protons	80 ^[9]
Radius of Atom
– Atomic radius	2.23 Å ^[1]
– Covalent radius	1.32 Å ^[1]
Electronegativity (Pauling-scale)	1.9 ^[1]
Electron affinity	Not stable ^[1]
Ionization energy (kJ mol^-1)	1st	2nd	3rd	4th	5th	6th	7th	8th
	1007.066	1809.756	3299.8	–	–	–	–	–

Mercury Electron Configuration (Bohr Model)

What is It Used for

It is used in electrical switches and rectifiers because of its high electrical conductivity, and as catalysts in the chemical industry ^[1].
It easily forms alloys (or amalgams) with other metals like silver, tin, zinc, and gold ^{[1, 2]}. The amalgams were previously used for extracting gold from the ores and also for producing dental fillings ^{[1, 2]}.
Mercuric sulfide, commonly called vermillion, is a bright-red pigment used for painting ^[1]. However, it is now cautiously used due to its high toxicity ^[1].
Mercury was commonly used in thermometers, barometers, batteries, fluorescent lights, and felt production [1, 7]. However, these have been discontinued ^[1].
Mercury compounds like HgCl₂ (mercuric chloride) and Hg₂Cl₂ (mercurous chloride) were used for disinfecting wounds and kill bacteria as an antiseptic respectively ^[2].

Mercury

Its Toxicity and Health Effects

Mercury and its compounds are poisonous ^{[1, 13]}. Exposure through skin contact, inhalation, or ingestion usually affects the kidneys, stomach, intestines, and the nervous system ^[13].

It exists in every living organism in little amounts and enters the human body through the food we eat, with the daily intake being less than 0.01 mg ^[1]. However, consuming large amounts of mercury, especially methylmercury, can cause severe illness and death ^[1].

Mercury is not known to play any biological roles ^[1].

Interesting Facts

Alchemists thought that combining mercury with other metals would help in turning it into gold ^[6].
Mercury weighs 13-14 times more than the same volume of water ^[6].
The graphical representation of mercury is an alchemical symbol, also indicating the planet Mercury ^[1].