Zirconium

Zirconium, ₄₀Zr

Zirconium
Pronunciation	/zɜːrˈkoʊniəm/ (listenⓘ) ​(zur-KOH-nee-əm)
Appearance	silvery white
Standard atomic weight Ar°(Zr)
	91.224(2)[1]
Zirconium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Ti ↑ Zr ↓ Hf yttrium ← zirconium → niobium
Atomic number (Z)	40
Group	group 4
Period	period 5
Block	d-block
Electron configuration	[Kr] 4d2 5s2
Electrons per shell	2, 8, 18, 10, 2
Physical properties
Phase at STP	solid
Melting point	2125 K ​(1852 °C, ​3365 °F)
Boiling point	4650 K ​(4377 °C, ​7911 °F)
Density (near r.t.)	6.52 g/cm3
when liquid (at m.p.)	5.8 g/cm3
Heat of fusion	14 kJ/mol
Heat of vaporization	591 kJ/mol
Molar heat capacity	25.36 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2639 2891 3197 3575 4053 4678
Atomic properties
Oxidation states	−2, 0, +1,[2] +2, +3, +4 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.33
Ionization energies	1st: 640.1 kJ/mol 2nd: 1270 kJ/mol 3rd: 2218 kJ/mol
Atomic radius	empirical: 160 pm
Covalent radius	175±7 pm
Spectral lines of zirconium
Other properties
Natural occurrence	primordial
Crystal structure	​hexagonal close-packed (hcp)
Speed of sound thin rod	3800 m/s (at 20 °C)
Thermal expansion	5.7 µm/(m⋅K) (at 25 °C)
Thermal conductivity	22.6 W/(m⋅K)
Electrical resistivity	421 nΩ⋅m (at 20 °C)
Magnetic ordering	paramagnetic[3]
Young's modulus	88 GPa
Shear modulus	33 GPa
Bulk modulus	91.1 GPa
Poisson ratio	0.34
Mohs hardness	5.0
Vickers hardness	820–1800 MPa
Brinell hardness	638–1880 MPa
CAS Number	7440-67-7
History
Naming	after zircon, zargun زرگون meaning "gold-colored".
Discovery	Martin Heinrich Klaproth (1789)
First isolation	Jöns Jakob Berzelius (1824)
Isotopes of zirconium v e
Main isotopes[4] Decay abun­dance half-life (t1/2) mode pro­duct 88Zr synth 83.4 d ε 88Y γ – 89Zr synth 78.4 h ε 89Y β+ 89Y γ – 90Zr 51.5% stable 91Zr 11.2% stable 92Zr 17.1% stable 93Zr trace 1.53×106 y β− 93Nb 94Zr 17.4% stable 96Zr 2.80% 2.34×1019 y β−β− 96Mo
Category: Zirconium view talk edit | references

Zirconium is a chemical elemental metal. It is a greyish-white in color. It is atomic number 40 on the periodic table. Its symbol is Zr. And it is in the family of four (4). Zirconium alloys are used as cladding for nuclear fuel rods.

Most zirconium is made from the mineral zircon. Zircon is also called zirconium silicate (ZrSiO₄). Zirconium is found in many types of sand and rock.^[5] These sources of zircon are crushed into a powder, separated using a centrifuge, and then treated with chemicals in a process called leaching. This separates the pure zircon from other minerals.^[source?]

Zircon needs to be split apart into zirconia and silica in order to purify it further. One way of doing this is alkaline fusion.^[6] In this chemical process, zircon is treated with a base like sodium hydroxide or sodium carbonate.

Zirconia is finally treated in the Kroll process to make pure zirconium metal.^[source?]

Further processing is needed to make nuclear-grade zirconium, because zirconium normally contains small amounts of hafnium, a neutron poison.^[source?]