Mercury (Hg)
Transition metal · d-block · period 6 · group 12
Dense, silvery, mirror-bright liquid metal.
Mercury (symbol Hg) is chemical element number 80, a transition metal in group 12, period 6 of the periodic table. Its standard atomic weight is 200.59 and its electron configuration is [Xe] 4f14 5d10 6s2. At room temperature it is a liquid. The only metal that is liquid at room temperature; its old name is 'quicksilver'.
Properties
| Atomic number | 80 |
|---|---|
| Atomic mass | 200.59 |
| Category | Transition metal |
| Block | d-block |
| Group · Period | 12 · 6 |
| Electron configuration | [Xe] 4f14 5d10 6s2 |
| Electrons per shell | 2, 8, 18, 32, 18, 2 |
| State at 25 °C | liquid |
| Melting point | 234.32 K |
| Boiling point | 629.88 K |
| Density | 13.534 g/cm³ |
| Electronegativity (Pauling) | 2 |
| Radioactive | No |
| Origin | primordial |
| Discovered | Known since antiquity · Known since antiquity |
Key facts about Mercury
- The only metal that is liquid at room temperature; its old name is 'quicksilver'.
- Its symbol Hg comes from 'hydrargyrum', Greek for 'water-silver'.
- A potent nerve poison — 'mad as a hatter' comes from hat-makers poisoned by mercury.
- Its vapour glows blue-white in fluorescent tubes and street lamps.
What Mercury is used for
Fluorescent lighting, thermometers and barometers (declining), dental amalgam, chlorine production, scientific instruments.
Where it sits in the periodic table
Mercury is in group 12, period 6, of the d-block. Its electron configuration [Xe] 4f14 5d10 6s2 means its outermost shell holds 2 electrons, which is what places it here and explains much of its chemistry. See Mercury on the interactive table →
Mercury — frequently asked questions
What is Mercury used for?
Fluorescent lighting, thermometers and barometers (declining), dental amalgam, chlorine production, scientific instruments.
Is Mercury radioactive?
No. Mercury has at least one stable isotope and is not radioactive.
What is the electron configuration of Mercury?
Mercury has the electron configuration [Xe] 4f14 5d10 6s2, which is 2, 8, 18, 32, 18, 2 electrons per shell.
What group and period is Mercury in?
Mercury is in group 12, period 6, in the d-block. Its outer shell holds 2 electrons.
Who discovered Mercury?
Mercury has been known since ancient times.