Element identity
Atomic number, symbol, relative atomic mass display and periodic position are established reference data.
Atomic / electronic model
Ground-state electron configuration and atomic reference values are compiled/evaluated data; orbital graphics are teaching probability models, not photographs.
Material / molecular structure
The displayed ordinary structure is based on established material or molecular science; simplified viewers are labelled as teaching schematics where exact crystallographic coordinates are not rendered.
Temperature / phase path
Transition values are reference/evaluated values for the stated teaching path; pressure, purity and allotropy can matter.
Geography
Real pins use reviewed place/dataset context. Conceptual layers are used when country pins would imply false occurrence, unsafe inventory or an incomplete global distribution.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Mercury (Hg)
Mercury is element 80, the only metallic element that is liquid under ordinary room conditions. Its signature science combines relativistic electronic effects, a low melting point, dense liquid behavior and a critical distinction between elemental mercury and highly varied mercury compounds.
Mercury atomic number, mass, electron configuration and key properties
Mercury: quick answers
How many protons, neutrons and electrons does mercury have?
Mercury’s atomic number is 80, so every mercury atom has 80 protons, and a neutral atom also has 80 electrons. Its most common natural isotope, mercury-202, has 122 neutrons (other isotopes have different neutron counts).
What is the symbol for mercury?
The chemical symbol for mercury is Hg.
Is mercury a solid, liquid or gas at room temperature?
Mercury is a liquid at room temperature (about 25 °C), one of only two elements that are.
What family (group) is mercury in?
Mercury is a transition metal, in group 12, period 6 of the periodic table.
What is the electron configuration of mercury?
The ground-state electron configuration of mercury is [Xe] 4f¹⁴ 5d¹⁰ 6s².
From atomic number to chemistry
Read these as a chain of causes, not as isolated facts. Each step links to the concept hub if you want the underlying idea explained.
Eighty protons define mercury.
Relativistic effects are important to mercury’s heavy-atom electronic structure.
Mercury lies below cadmium.
Mercury melts at only about 234.3 K.
Natural mercury has a rich stable-isotope pattern.
Mercury in its period and family
Mercury is in Group 12 below cadmium. Relativistic stabilization of the 6s electrons contributes to its unusual weak metallic bonding and low melting point, though the full condensed-matter explanation is more complex than a single effect.
Mercury Visual Lab
Decode mercury’s tile, compare Hg and Hg²⁺ shell counts, rotate a ²⁰²Hg teaching nucleus and low-temperature rhombohedral lattice, inspect 6s and representative 5d probability models, and connect phase behavior to historical instruments, gold-mining pollution, environmental cycling and safer alternatives.
Every mark points to one exact feature
The numbered markers explain the same information system used throughout Element Lookup. Unknown or predicted fields remain visibly labelled rather than being replaced with guesses.
Mercury in one minute
Atomic number 80 means every mercury nucleus contains 80 protons.
Neutral mercury has the ground-state configuration [Xe] 4f¹⁴ 5d¹⁰ 6s².
Mercury is liquid at ordinary room temperature because its melting point is only 234.321 K.
Below its freezing point, solid α-mercury is rhombohedral.
Mercury toxicity depends strongly on chemical form and exposure pathway; elemental, inorganic and organic mercury species are not interchangeable.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 18 · 2 electrons
The 6s and representative 5d models are isolated-atom probability distributions. Relativistic effects are especially important for mercury, so these nonrelativistic teaching shapes are not a complete explanation of liquid-metal behavior.
Mercury is liquid at room temperature. Below its freezing point, α-Hg adopts a rhombohedral structure; the viewer is a simplified low-temperature lattice schematic and not a claim that room-temperature mercury is crystalline.. The viewer is evidence-aware: measured structures are identified as such; unknown bulk structures stay unknown.
Teaching visualization; not a literal finite sample or thermal trajectory.What this model does—and does not—show
The 6s and representative 5d models are isolated-atom probability distributions. Relativistic effects are especially important for mercury, so these nonrelativistic teaching shapes are not a complete explanation of liquid-metal behavior.
Where do I meet mercury?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Liquid metal
Mercury’s low melting point made it useful historically in thermometers, barometers and switches, though many applications have shifted to safer alternatives.
Why mercury is a liquid metal - and why “mercury” is not one exposure category
Mercury combines unusual heavy-atom bonding with species-dependent environmental chemistry.
Elemental mercury
At room temperature elemental mercury is a dense liquid metal because its melting point is below ordinary room temperature.
Zinc, cadmium and mercury: why the bottom element breaks expectations
All three have filled d subshells, yet mercury’s heavy-atom electronic structure leads to extraordinary bulk behavior.
| State | solid |
|---|---|
| Melt | 692.7 K |
| State | solid |
|---|---|
| Context | heavier Group 12 metal |
| State | liquid |
|---|---|
| Melt | 234.3 K |
| Relativity | important |
Mercury properties: atomic, physical, thermal and chemical
Categories follow the science of this element rather than a fixed decorative template. Each row carries condition/provenance context and an evidence label; unknown values stay unknown.
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Atomic number | 80 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 200.592 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 12 · Period 6 · d-block | Periodic-table placement | Evaluated |
| Electronegativity | 2.00 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ²⁰²Hg | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Dense liquid metal at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 13.5336 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | α-mercury · rhombohedral below freezing | Mercury is liquid at room temperature. Below its freezing point, α-Hg adopts a rhombohedral structure; the viewer is a simplified low-temperature lattice schematic and not a claim that room-temperature mercury is crystalline. | Measured |
| Classification | Group 12 metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Mercury is liquid at room temperature. Below its freezing point, α-Hg adopts a rhombohedral structure; the viewer is a simplified low-temperature lattice schematic and not a claim that room-temperature mercury is crystalline. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 234.321 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 629.769 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, mercury is solid below 234.321 K, liquid from 234.321 K to about 629.769 K, and gaseous above. The material viewer shows the low-temperature solid lattice, while the page clearly labels mercury as liquid at room temperature. | Shared phase registry drives the slider, regions and markers. | Evaluated |
| Condition warning | Temperature and pressure define phase behavior; purity/allotropy may matter. | Teaching condition statement | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Ordinary electrical behavior | Metallic conductor | Qualitative bulk behavior; exact resistivity depends on temperature, purity and alloy state. | Measured |
| Conduction model | Collective solid-state electrons | Do not interpret isolated-atom orbital clouds as literal current paths. | Reviewed |
| Surface / compound caveat | Oxides, salts and alloys can behave differently from the pure metal | Material context | Reviewed |
| Engineering values | Condition-dependent | Use condition-specific materials data for engineering calculations. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Common oxidation states | +1 (Hg₂²⁺) and +2 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Hg²⁺ · Hg₂²⁺ also important | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Mercury is in Group 12 below cadmium. Relativistic stabilization of the 6s electrons contributes to its unusual weak metallic bonding and low melting point, though the full condensed-matter explanation is more complex than a single effect. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ²⁰²Hg | Stable · most abundant natural isotope | Teaching nucleus contains 80 protons and 122 neutrons. | Evaluated |
| ²⁰⁰Hg | Stable · major natural isotope | One of several stable mercury isotopes contributing to natural atomic weight. | Evaluated |
| ¹⁹⁹Hg and ²⁰¹Hg | Stable · NMR-active isotopes | Important in isotope and spectroscopy studies. | Evaluated |
| Mercury isotope family | Seven stable natural isotopes | Natural mercury has a rich stable-isotope pattern used in geochemical tracing. | Evaluated |
| Teaching nucleus | ²⁰²Hg · 80 protons + 122 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Mercury a solid, liquid or gas? State at temperature
At approximately standard pressure, mercury is solid below 234.321 K, liquid from 234.321 K to about 629.769 K, and gaseous above. The material viewer shows the low-temperature solid lattice, while the page clearly labels mercury as liquid at room temperature.
Where on Earth is Mercury found or produced?
Who discovered Mercury, and when?
Cinnabar and mercury were known in antiquity and used in pigments, metallurgy and medicine despite hazards.
Torricelli’s mercury barometer became a classic demonstration of atmospheric pressure.
Mercury became common in instruments, switches, lamps and industrial chemistry.
Recognition of global pollution and health impacts drove substitution, tighter controls and the Minamata Convention on Mercury.
Mercury’s material cycle: high-level environmental context
Mercury occurs in ores such as cinnabar and can also be released as a by-product or impurity from other industrial activities.
Historically, roasting mercury ores produced mercury vapor for condensation; this guide intentionally does not provide operational extraction instructions.
Mercury-containing products and industrial uses increasingly face substitution, collection and emission-control requirements.
Environmental management focuses on preventing releases and limiting conversion to forms such as methylmercury that bioaccumulate in food webs.
What is mercury used for?
Legacy instruments
Mercury’s liquid range and density supported thermometers, barometers and switches, but safer replacements are now common.
Discharge lighting
Mercury vapor has been used in fluorescent and other discharge lamps, creating a need for controlled end-of-life handling.
Specialized scientific uses
Some reference electrodes and specialized equipment still use mercury under controlled laboratory conditions.
Historical amalgamation
Mercury has been used to recover gold; uncontrolled use creates severe health and environmental risks and is not endorsed here.
Mercury isotopes and natural abundance
²⁰²Hg
Stable · most abundant natural isotopeTeaching nucleus contains 80 protons and 122 neutrons.
²⁰⁰Hg
Stable · major natural isotopeOne of several stable mercury isotopes contributing to natural atomic weight.
¹⁹⁹Hg and ²⁰¹Hg
Stable · NMR-active isotopesImportant in isotope and spectroscopy studies.
Mercury isotope family
Seven stable natural isotopesNatural mercury has a rich stable-isotope pattern used in geochemical tracing.
Five-question Mercury check
What is mercury’s atomic number?
What is mercury’s physical state near 20 °C?
What is mercury’s symbol?
Which statement is scientifically best?
What structure does solid α-mercury adopt below freezing?
Mercury questions students commonly ask
Each answer starts with the direct fact, then explains the chemistry, evidence or material context so the result is understandable rather than merely memorized.
Why is mercury liquid at room temperature?
Short answer: Mercury melts at about −38.8 °C, so ordinary room temperature lies well above its melting point. Its unusually weak Hg–Hg cohesion is tied to its closed-shell electronic structure and important relativistic effects in heavy mercury atoms.
A useful advanced explanation focuses on bonding in elemental mercury rather than on a single slogan. Relativistic stabilization/contraction of the 6s electrons and the filled 5d¹⁰6s² configuration reduce the effectiveness of metallic bonding compared with many neighboring metals. The result is a low melting point for a metal. The exact phase boundary is measured; the electronic explanation comes from theory and spectroscopy-supported models.
Key point: Separate the measured fact (melting point) from the electronic-structure explanation for why Hg–Hg bonding is unusually weak.
What is mercury’s element symbol?
Short answer: Hg, from the Latin hydrargyrum.
The symbol Hg is the standardized chemical abbreviation for element 80. In a chemical formula, Hg identifies mercury atoms; a compound containing Hg is not automatically the same material as elemental mercury.
Key point: Hg always identifies element 80.
What is mercury’s atomic number?
Short answer: 80.
Atomic number is defined by proton count, so 80 protons are what make an atom mercury. A neutral mercury atom also has 80 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
Where is mercury found naturally?
Short answer: Mostly in compounds and trace occurrences, with cinnabar (HgS) the classic ore mineral; free elemental mercury is not the dominant natural form.
Mercury occurs in ores such as cinnabar and can also be released as a by-product or impurity from other industrial activities. ²⁰⁰Hg Stable · major natural isotope One of several stable mercury isotopes contributing to natural atomic weight.
Key point: Natural occurrence, resources, production and recycling are different geography questions.
Why is mercury dangerous, and are all mercury forms equally hazardous?
Short answer: No. Hazard depends strongly on chemical form and exposure route: elemental mercury vapor, inorganic mercury compounds and organic mercury species such as methylmercury have different absorption, distribution and toxic effects.
For spilled elemental mercury, inhalation of vapor is a major concern because mercury vapor can be absorbed through the lungs. Inorganic Hg²⁺ compounds and organic mercury species behave differently in the body; methylmercury is especially important for neurological exposure through food chains. “Mercury” is therefore not one interchangeable toxicological object.
Key point: Always name the mercury species and exposure route before describing risk.
Who discovered mercury?
Short answer: Mercury was known in antiquity, so it does not have a single modern discoverer.
In the ancient world, Cinnabar and mercury were known in antiquity and used in pigments, metallurgy and medicine despite hazards. In 1643, Torricelli’s mercury barometer became a classic demonstration of atmospheric pressure.
Key point: Discovery credit follows the historical evidence and accepted attribution, not just the earliest claim.
What is mercury used for today?
Short answer: Modern uses are specialized and increasingly controlled; they include some scientific instruments, discharge lighting and regulated industrial applications. Many older uses have been replaced because of mercury hazards.
Legacy instruments: Mercury’s liquid range and density supported thermometers, barometers and switches, but safer replacements are now common. Discharge lighting: Mercury vapor has been used in fluorescent and other discharge lamps, creating a need for controlled end-of-life handling. A silvery mercury droplet is visually memorable, but mercury’s most important modern lesson is species and exposure: elemental Hg, inorganic Hg compounds and methylmercury behave differently.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Scientific sources for Mercury
- Royal Society of Chemistry - Mercury
- NIST - Atomic Data for Mercury
- Minamata Convention on Mercury
- WHO - Mercury and health
- RSC — Mercury
- ATSDR — Mercury toxicological profile
Questions to ask next about Mercury
A good element lesson should lead to the next useful question, not end after a list of facts.
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