Periodic Table

Zirconium

Transition Metal

Quick Facts about Zirconium

Y
  • solid- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +4- common oxidation states in compounds
  • HEX- crystal structure, atomic arrangement in solid form
Nb

Zirconium (Zr) is element 40 on the periodic table. Atomic mass of Zr: 91.2240 u. Zr is in period 5, group 4. Melting point of Zr: 2128.00 K.Density of Zr: 6.52 g/cm³.

Why Zirconium Matters

Zirconium in everyday life and industry

In Your Home

  • Cubic zirconia is a popular diamond substitute in jewelry
  • Antiperspirants often contain zirconium compounds
  • High-performance ceramics like dental crowns use zirconium oxide

Industry Uses

NuclearNuclear reactor fuel rods are clad in zirconium alloys

In Your Body

✗ Not essential

Zirconium has no known biological role in humans. The body absorbs very little zirconium from food or water. Some people develop skin sensitivity to zirconium in antiperspirants.

Safety: Zirconium compounds are generally considered non-toxic

Discovery of Zirconium

Discovered by Martin Klaproth in Germany, 1789

Name origin: From the mineral, zircon.

History & Events

1789
Named from Persian 'zargun' meaning 'gold-colored' (for zircon gemstones)
1824
Isolated by Berzelius in 1824 by heating potassium zirconium fluoride
1789
Became critical for nuclear technology in the 1950s
1789
Ancient Egyptians and Greeks used zircon gemstones as decorations

About Zirconium

Grey-white metallic transition element. Five natural isotopes and six radioactive isotopes are known. Used in nuclear reactors for a Neutron absorber. Discovered in 1789 by Martin Klaproth, isolated in 1824 by Berzelius.

Atomic Properties of Zr

Atomic Number of Zr
40
Atomic Mass of Zr
91.2240 u
Electron Configuration
[Kr] 4d2 5s2
Electronegativity
1.33
Block
d-block
Group
4
Period
5

Physical Properties of Zr

Phase (STP)
solid
Melting Point of Zr
2128.00 K
Boiling Point of Zr
4650.00 K
Density of Zr
6.5200 g/cm3

Thermal Properties

Heat of Fusion
19.20 kJ/mol
Heat of Vaporization
567.00 kJ/mol
Specific Heat
0.28 J/g·K
Molar Heat Capacity
25.36 J/mol·K
Thermal Conductivity
22.70 W/m·K

Atomic Radii

Calculated
155 pm
Covalent
154 pm
Van der Waals
223 pm
Metallic
145 pm

Common Misconceptions

Wrong:Cubic zirconia is the same as zircon.
Correct:Zircon (ZrSiO4) is a natural gemstone. Cubic zirconia (ZrO2) is lab-made and used as a cheap diamond substitute—completely different minerals.
Wrong:Zirconium is radioactive.
Correct:Zirconium isn't radioactive, though it's found with radioactive hafnium in nature
Wrong:Despite similar names, zirconium and zircon (the gemstone) are different.
Correct:Zircon is zirconium silicate

Isotopes of Zirconium

Zirconium has 5 naturally occurring isotopes.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
9040Zr (Zr-90)Zirconium-90 isotope89.904697751.45%
9140Zr (Zr-91)Zirconium-91 isotope90.905639611.22%
9240Zr (Zr-92)Zirconium-92 isotope91.905034717.15%
9440Zr (Zr-94)Zirconium-94 isotope93.906310817.38%
9640Zr (Zr-96)Zirconium-96 isotope95.90827142.800%

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Zirconium have important real-world applications in science and industry.

Industrial Applications

Zirconium enriched in 90Zr has been proposed for the cladding (covering) of reactor fuel elements (Fig. IUPAC.40.1) because it has a lower neutron absorption cross section than natural abundances of zirconium and is well suited for coverage of metal parts without absorbing neutrons [307].

Abundance

Earth's Crust
165.0 mg/kg
Seawater
3.00×10-5 mg/L

Uses

Used in alloys such as zircaloy which is used in nuclear applications since it does not readily absorb neutrons. Also baddeleyite is used in lab crucibles. Used in high-performance pumps and valves. Clear zircon (ZrSiO4) is a popular gemstone.

Sources

Found in many minerals such as zircon and baddeleyite.

Geochemistry

Goldschmidt
litophile
Geochemical Class
high field strength

Test Your Knowledge

Loading quiz...