Category: Transition metal
Atomic Number: 40
Period: 5 | Group: 4
Block: d-block
Effectively transparent to neutrons, which is why it lines the fuel rods in nearly every nuclear reactor.
| Property | Value |
|---|---|
| Phase at STP | Solid |
| Density | N/A |
| Melting Point | 2128.00 K (1854.85 °C) |
| Boiling Point | 4682.00 K (4408.85 °C) |
| Heat Capacity | N/A |
| Property | Value |
|---|---|
| Atomic Mass | 91.2240 u |
| Electronegativity (Pauling) | N/A |
| Oxidation States | +2, +3, +4 |
| Electron Configuration |
| Discovered By | Unknown |
|---|---|
| Discovery Year | 1789 |
| Named After | Persian zargun, "gold-coloured" |
The Gemstone Element
Martin Heinrich Klaproth discovered zirconium in 1789 while analyzing zircon gemstones. Jöns Jakob Berzelius first isolated impure zirconium metal in 1824, though pure zirconium was first made by the van Arkel-de Boer crystal bar process in 1925.
| ISOTOPE | Neutrons | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|---|
| Zr-90 | 50 | 51.45% | Stable | - |
| Zr-91 | 51 | 11.22% | Stable | - |
| Zr-92 | 52 | 17.15% | Stable | - |
| Zr-94 | 54 | 17.38% | Stable | - |
| Zr-96 | 56 | 2.80% | 2.0 × 10¹⁹ yrs | - |
Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.
Zirconium: The Nuclear Guardian
Zirconium's exceptional corrosion resistance and low neutron absorption make it indispensable for nuclear reactors, while its biocompatibility and strength enable advanced medical implants and aerospace applications.
Nuclear Reactor Applications
Zircaloy fuel cladding encases uranium fuel pellets in nuclear reactors, providing corrosion resistance in high-temperature water while allowing neutron transmission for sustained nuclear fission. Zirconium's low neutron absorption cross-section makes it ideal for reactor core components where neutron economy is critical.
Chemical Processing
Zirconium equipment handles highly corrosive chemicals including hydrochloric acid, sulfuric acid, and organic acids at temperatures and concentrations that destroy stainless steel within hours. Pharmaceutical and fine chemical manufacturing rely on zirconium's chemical inertness for high-purity processing.
Aerospace Applications
Zirconium alloys provide exceptional strength-to-weight ratios for aircraft components operating in corrosive environments. Space applications utilize zirconium's resistance to atomic oxygen and thermal cycling in satellite structural components.
| Earth's Crust | N/A |
|---|---|
| Universe | N/A |