Mercury is a metal that is liquid at ordinary room temperature and forms amalgams with several other metals. It has a history in instruments, switches, and pigments. Its toxicity and differing chemical forms make it a useful example of why material behavior cannot be inferred from appearance alone.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How did mercury instruments translate a physical change into a readable scale?
Elemental mercury in a sealed instrument
FOLLOW THIS RELATIONSHIP
Confine the liquid in an instrument
A historical thermometer or barometer contained elemental liquid mercury in a defined geometry. The instrument used bulk fluid behavior rather than a mercury pigment.
Explore the model (optional)
HgFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
Why cannot one infer temperature from every mercury-column position?
Atomic identity, reference properties and structure models
INTERACTIVE 3D80 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Xe] 4f14 5d10 6s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Mercury and its red , cinnabar, were known in antiquity. The liquid metal's ability to form amalgams with gold led to extensive use in extraction; California's 1848 gold rush drew on mercury from nearby mining. These histories should not romanticize an attractive material: mercury's mobility and toxicity connect past technology to enduring environmental consequences, while cinnabar pigment and elemental liquid remain chemically different substances.
Antiquity
Cinnabar and mercury known
People used mercury-bearing material long before modern elemental theory.
1848
Gold-rush demand
California gold extraction used mercury supplied by local mining.
Cinnabar, mercury sulfide, is an important mercury mineral, and small occurrences of native liquid mercury are also known. Mining and processing can move mercury into new environments and chemical forms. The red mineral, elemental liquid, and organic mercury compounds therefore should not be collapsed into one undifferentiated material.
Mercury is liquid at ordinary room temperature and can form amalgams with selected metals. It also releases vapor, and its compounds differ in mobility and biological behavior. These distinctions explain why historical measuring devices, a fluorescent-lamp discharge, and environmental mercury chemistry require separate descriptions rather than one universal property list.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
liquid
293.15 K, 101.325 kPa
Melting point in K
234.32 K
at standard pressure unless noted
Boiling point in K
629.88 K
101.325 kPa
Density in g/cm³
13.53 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
2 Pauling
Pauling scale
First ionization energy in kJ/mol
1007 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
132 pm
single-bond covalent radius
Common oxidation states
+1, +2
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
0.085 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year
Not recorded
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 6
Hg 2 Pauling · Mercury
Electronegativity across period 6. Exact values.
Cs
0.79
Ba
0.89
La
1.1
Ce
1.12
Pr
1.13
Nd
1.14
Sm
1.17
Eu
1.2
Gd
1.2
Tb
1.1
Dy
1.22
Ho
1.23
Er
1.24
Tm
1.25
Yb
1.1
Lu
1.27
Hf
1.3
Ta
1.5
W
2.36
Re
1.9
Os
2.2
Ir
2.2
Pt
2.28
Au
2.54
Hg
2
Tl
1.62
Pb
2.33
Bi
2.02
Po
2
At
2.2
Electronegativity down group 12
Hg 2 Pauling · Mercury
Electronegativity down group 12. Exact values.
Zn
1.65
Cd
1.69
Hg
2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
