40ZrZirconium91.2242[Kr] 4d² 5s²
transition metal

Zirconium

Zirconium is a chemical element with symbol Zr and atomic number 40. The name of zirconium is taken from the name of the mineral zircon, the most important source of zirconium. The word zircon comes from the Persian word zargun زرگون, meaning "gold-colored".

Electronic structure

A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.

Electrons by shell
Electron configuration
4d2
5s2

36 is the [Kr] core total across four shells.

Properties

At a glance

Atomic number
40
Atomic mass
91.2242 u
Phase
Solid
Density
6.52 g/cm³
Melting point
2,128 K
Boiling point
4,650 K
First ionization energy
640.1 kJ/mol
Electronegativity
1.33
Electron affinity
41.806 kJ/mol
Molar heat capacity
25.36 J/(mol·K)
Period
5
Appearance
silvery white

Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.

Keep exploring

Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.