Zirconium (Zr)
Zirconium (Zr) is element 40, a transition metal. Atomic mass 91.222, configuration [Kr] 4d² 5s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 40 |
|---|---|
| Symbol | Zr |
| Standard atomic weight | 91.222(3) |
| Category | Transition Metal |
| Group | 4 |
| Period | 5 |
| State at room temperature | Solid |
| Electron configuration | [Kr] 4d² 5s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +4 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.33 |
| First ionization energy | 640 kJ/mol |
| Electron affinity | 41.1 kJ/mol |
| Atomic radius | 206 pm |
| Density | 6.52 g/cm³ |
| Melting point | 1855°C |
| Boiling point | 4409°C |
| Specific heat | 0.278 J/(g·°C) |
Natural isotopes
- Zr-90: Stable
- Zr-91: Stable
- Zr-92: Stable
- Zr-94: Stable
Common uses
- Nuclear fuel cladding
- Chemical piping
- Fake diamonds (CZ)
Where it matters
- Nuclear energy (Fuel rod cladding due to low neutron absorption)
- Gemstones
Hazards
- Powder is highly flammable/explosive
- biologically inert
History
| Discovered | 1789 |
|---|---|
| Discovered by | Martin Heinrich Klaproth |
| Name | From Persian zargun (gold-colored) |