Mercury
Mercury is a toxic metal that is liquid near room temperature.
Mercury is a familiar exception to the usual picture of a solid metal.
Explore Mercury's atom- Atomic number
- 80
- Standard atomic weight
- 200.592(3)
- Family
- Transition metal
- Period
- 6
- Group
- 12
- Standard state
- Liquid
In everyday life
Some older thermometers and lamps contain mercury; many uses have been phased out.
Something to remember
Mercury is a metal that is liquid at typical room temperature.
Meet its electrons
[Xe] 6s2 4f14 5d10
Published neutral-atom ground-state configuration; excited atoms and ions can differ.
Electrons per shell: 2 · 8 · 18 · 32 · 18 · 2.
The playground shows an illustrative shell model. Real electrons are described by quantum orbitals, rather than tiny planets traveling along fixed paths.
A connection to explore
Mercury and zinc share a group, but only mercury is liquid at typical room temperature.
Meet Zinc (Zn)Properties and conditions
- Standard atomic weight
- 200.592(3)CIAAW 2024 standard atomic weight (dimensionless). Parentheses give uncertainty in the last quoted digits. Source flags: none.CIAAW standard atomic weights ↗ · Retrieved 2026-10-15
- Standard state
- LiquidPubChem classification, including explicit predictions where stated. Reference temperature and pressure are not supplied in the table.PubChem periodic table ↗ · Retrieved 2026-10-15
- First ionisation energy
- 10.438 eVEnergy to remove the first electron from an isolated neutral gas-phase atom. Uncertainty is not supplied.PubChem periodic table ↗ · Retrieved 2026-10-15
- Electronegativity
- 2 Pauling scaleA dimensionless relative measure; values depend on the chosen scale. Uncertainty is not supplied.PubChem periodic table ↗ · Retrieved 2026-10-15
- Melting point
- 234.32 KPubChem reported value. Pressure, allotrope and measurement uncertainty are not specified in the table; consult the cited source.PubChem periodic table ↗ · Retrieved 2026-10-15
- Boiling point
- 629.88 KPubChem reported value. Pressure and measurement uncertainty are not specified in the table; consult the cited source.PubChem periodic table ↗ · Retrieved 2026-10-15
- Density
- 13.5336 g/cm³PubChem reported value. Temperature, pressure, allotrope and measurement uncertainty are not specified in the table; gas densities are especially condition-dependent.PubChem periodic table ↗ · Retrieved 2026-10-15
- Oxidation states
- +2, +1Selected PubChem oxidation states; formal electron bookkeeping, not a list of stable free-ion charges or every possible compound.PubChem periodic table ↗ · Retrieved 2026-10-15
- Discovery
- AncientPubChem discovery attribution. Ancient knowledge and competing priority claims cannot always be represented by a single year.PubChem periodic table ↗ · Retrieved 2026-10-15
- Atomic radius
- 209 pmPubChem tabulated radius. Radius definitions depend on bonding and convention; measurement definition and uncertainty are not supplied in this table.PubChem periodic table ↗ · Retrieved 2026-10-15
- Electron affinity
- Not reportedPubChem reported gas-phase electron affinity. Sign conventions and electronic states matter; uncertainty is not supplied in this table.PubChem periodic table ↗ · Retrieved 2026-10-15
Isotopes, abundance and decay
Isotopes share a proton count but have different neutron counts. This selection includes naturally tabulated compositions and a reference isotope for other elements. It is not a list of every known isotope.
Explore 7 isotopes of Hg
| Isotope | Relative atomic mass | Natural fraction | Half-life | Decay |
|---|---|---|---|---|
| Hg-196 | 195.9658326(32) | 0.0015(1) | No decay observed | ;2β+ ? |
| Hg-198 | 197.96676860(52) | 0.0997(20) | No decay observed | No decay tabulated |
| Hg-199 | 198.96828064(46) | 0.1687(22) | No decay observed | No decay tabulated |
| Hg-200 | 199.96832659(47) | 0.2310(19) | No decay observed | No decay tabulated |
| Hg-201 | 200.97030284(69) | 0.1318(9) | No decay observed | No decay tabulated |
| Hg-202 | 201.97064340(69) | 0.2986(26) | No decay observed | No decay tabulated |
| Hg-204 | 203.97349398(53) | 0.0687(15) | No decay observed | ;2β− ? |
Fractions use NIST’s terrestrial isotopic compositions, which can vary by sample. Parentheses denote uncertainty in the last digits. Half-lives and decay branches use NUBASE2020; # marks estimates, >/< mark limits. “No decay observed” follows that evaluation and does not prove permanent stability. Decay branch intensities are percentages; SF means spontaneous fission, EC electron capture, IT an isomeric transition.
Follow the science
Use these original references to explore the data and context. Atomic weights can vary with isotope composition; values for elements without stable isotopes may describe a representative isotope rather than a standard atomic weight.