Atomic number 80
Mercury
Transition metal
Quick facts
- Atomic mass
- 200.59
- Group
- 12
- Period
- 6
- State (STP)
- liquid
- Electronegativity
- 2.00
- Common ox. states
- +1, +2
Properties
Electron configuration
[Xe] 4f¹⁴ 5d¹⁰ 6s²
- Ionization energy
- 1007.1 kJ/mol
- Electron affinity
- -48.0 kJ/mol
- Melting point
- 234.32 K (-38.8 °C)
- Boiling point
- 629.88 K (356.7 °C)
How it bonds
Mercury is the only metal liquid at room temperature — relativistic effects pull the 6s electrons in close, weakening Hg-Hg metallic bonds. Forms +1 (Hg₂²⁺, an unusual paired ion) and +2 (HgCl₂). Toxic in essentially every form; methylmercury bioaccumulates in fish.