ZIRCONIUM
TRANSITION ELEMENT: TITANIUM GROUP
| Atomic number: | 40 |
| Group numbers: | 4 |
| Period: | 5 |
| Electronic configuration: | [Kr] 4d2 5s2 |
| Formal oxidation number: | +4 |
| Electronegativities: | 1.33 |
| Atomic radius / pm: | 159 |
| Relative atomic mass: | 91.224(2) |
Zirconium was discovered by Martin Heinrich Klaproth (DE) in 1789. The origin of the name comes from the Arabic word zargun meaning gold colour. It is a grey-white, lustrous, corrosion-resistant metal. Exposed surfaces form oxide protective film. Zirconium is found in many minerals such as zircon and baddeleyite. It is used in alloys such as zircaloy which is used in nuclear applications since it does not readily absorb neutrons. Zirconium is used in high-performance pumps and valves. Clear zircon (ZrSiO4) is a popular gemstone. The price of 99.5 % pure zirconium slug is 81.50 € for 100 g.
| Density / g dm-3: | 6506 | (293 K) |
| 5800 | (m.p.) | |
| Molar volume / cm3mol-1: | 14.02 | (293 K) |
| 15.73 | (m.p.) | |
| Electrical resistivity / µΩcm: | 42.1 | (20 °C) |
| Thermal conductivity / W m-1K-1: | 22.7 |
| Melting point / °C: | 1855 |
| Boiling point / °C: | 4409 |
| Heat of fusion / kJ mol-1: | 23 |
| Heat of vaporization / kJ mol-1: | 566.7 |
| Heat of atomization / kJ mol-1: | 607.47 |
| First ionization energy / kJ mol-1: | 640.08 |
| Second ionization energy / kJ mol-1: | 1266.86 |
| Third ionization energy / kJ mol-1: | 2218.21 |
| in the atmosphere / ppm: | - |
| in the Earth's crust / ppm: | 100 |
| in the oceans / ppm: | 0.000026 |
| Crystal structure: | hexagonal |
| Unit-cell dimensions / pm: | a=323.21, c=514.77 |
| Space group: | P63/mmc |
| Isotope | Relative atomic mass | Mass percent (%) |
|---|---|---|
| 90Zr | 89.904704(2) | 51.45(3) |
| 91Zr | 90.905645(2) | 11.22(4) |
| 92Zr | 91.905040(2) | 17.15(2) |
| 94Zr | 93.906316(3) | 17.38(4) |
| 96Zr | 95.908276(3) | 2.80(2) |
| Balanced half-reaction | Eo / V | |
|---|---|---|
| Zr4+ + 4e- → Zr(s) | - 1.539 | |
| H2ZrO3(s) + H2O + 4e- → Zr(s) + 4OH- | - 2.36 | |
| HZrO3- + 5H+ + 4e- → Zr(s) + 3H2O | - 1.276 | |
| ZrO2+ + 2H+ + 4e- → Zr(s) + H2O | - 1.570 | |
| ZrO2(s) + 4H+ + 4e- → Zr(s) + 2H2O | - 1.456 | |
| ZrO2×H2O(s) + 4H+ + 4e- → Zr(s) + 3H2O | - 1.533 | |
| ZrO2×2H2O + 4H+ + 4e- → Zr(s) + 4H2O | - 1.553 |
| 39 Yttrium | ← | 40 Zirconium | → | 41 Niobium |
Citing this page:
Generalic, Eni. "Zirconium." EniG. Periodic Table of the Elements. KTF-Split, 13 Feb. 2025. Web. {Date of access}. <https://www.periodni.com/zr.html>.
