Mercury
Definition and meaning of Mercury in chemistry.
![Mercury element card: symbol Hg, atomic number 80, atomic mass 200.59, electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s², oxidation states +2 +1, Transition metal, group 12, period 6, liquid at room temperature.](/assets/images/terms/mercury-chemical-element.webp)
Mercury is a chemical element with the symbol Hg and atomic number 80. People historically called it quicksilver because of its shiny silvery appearance and fluid state. This heavy, highly toxic transition metal is uniquely fascinating to chemists. It is the only metallic element that remains liquid at standard room temperature and pressure.
In more detail
Mercury sits securely in group 12 of the periodic table. It is a relatively poor conductor of heat but acts as a fair conductor of electricity. It possesses an unusually low melting point due to its extremely stable, fully filled 6s electron subshell.
You will rarely find liquid mercury freely occurring in nature. Instead, miners primarily extract it from cinnabar, which is a bright red mercuric sulfide ore. They heat the mineral in a current of air and then carefully condense the resulting metallic vapor.
Mercury displays a strong tendency to form special metallic alloys known as amalgams. It amalgamates easily with many common metals, including gold, silver, and tin. Interestingly, the liquid metal does not form these amalgam alloys when mixed with iron.
When reacting chemically, mercury exists primarily in the +1 and +2 oxidation states. It forms a wide variety of organic and inorganic chemical compounds. Unfortunately, these mercury compounds are highly toxic to the central nervous and endocrine systems.
Because of these severe health and environmental hazards, governments regulate the element strictly. They have drastically curtailed its industrial use through various global international agreements.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Hg |
| Atomic number | 80 |
| Atomic mass | 200.59 u |
| Category | Transition-Metal |
| State at room temperature | Liquid |
Despite widespread global phase-outs, mercury is still utilized in the construction of certain specialized scientific instruments. You can find it enclosed in traditional laboratory barometers and manometers. Its incredibly high density allows for highly compact and accurate pressure measurements in the laboratory.
Frequently asked questions
Why is mercury a liquid at room temperature?
The relativistic contraction of its orbitals causes the nucleus to hold the outermost 6s electrons very tightly. This strange effect prevents the atoms from sharing electrons to form strong metallic bonds.
How does mercury poisoning affect the human body?
Mercury exposure severely damages the human central nervous system. It directly leads to cognitive impairment, body tremors, muscle weakness, and profound neurodevelopmental issues in fetuses.
Related terms
Sources & references
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