Zirconium

Zirconium is a chemical element wi the seembol Zr, atomic nummer 40 an atomic mass o 91.224. The name o zirconium is taken frae the mineral zircon, the maist important soorce o zirconium, an frae the Persian wird "zargun - زرگون", meanin "gold colored". It is a lustrous, grey-white, strang transeetion metal that resembles titanium. Zirconium is mainly uised as a refractory an opacifier, altho it is uised in smaa amoonts as an alloyin agent for its strang resistance tae corrosion. Zirconium forms a variety o inorganic an organometallic compoonds sic as zirconium dioxide an zirconocene dichloride, respectively. Five isotopes occur naiturally, three o which are stable. Zirconium compoonds hae na kent biological role.

Zirconium,  ₄₀Zr

General properties
Appearance	sillery white
Staundart atomic wecht (Ar, staundart)	7001912240000000000♠91.224(2)
Zirconium in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Gowd Mercur (element) Thallium Leid (element) 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium Ti ↑ Zr ↓ Hf yttrium ← zirconium → niobium
Atomic nummer (Z)	40
Group	group 4
Period	period 5
Element category	transition metal
Block	d-block
Electron confeeguration	[Kr] 5s2 4d2
Electrons per shell	2, 8, 18, 10, 2
Pheesical properties
Phase (at STP)	solit
Meltin pynt	2128 K ​(1855 °C, ​3371 °F)
Bylin pynt	4682 K ​(4409 °C, ​7968 °F)
Density (near r.t.)	6.52 g/cm3
when liquid (at m.p.)	5.8 g/cm3
Heat o fusion	14 kJ/mol
Heat o vapourisation	573 kJ/mol
Molar heat capacity	25.36 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2639 2891 3197 3575 4053 4678
Atomic properties
Oxidation states	4, 3, 2, 1 (amphoteric oxide)
Electronegativity	Pauling scale: 1.33
Atomic radius	empirical: 160 pm
Covalent radius	175±7 pm
Spectral lines o Zirconium
Miscellanea
Creestal structur	​hexagonal close-packed (hcp)
Speed o soond 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 n Ω·m (at 20 °C)
Magnetic orderin	paramagnetic
Young's modulus	88 GPa
Shear modulus	33 GPa
Bouk modulus	91.1 GPa
Poisson ratio	0.34
Mohs haurdness	5.0
Vickers haurdness	903 MPa
Brinell haurdness	650 MPa
CAS Nummer	7440-67-7
History
Diskivery	Martin Heinrich Klaproth (1789)
First isolation	Jöns Jakob Berzelius (1824)
Main isotopes o zirconium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 88Zr syn 83.4 d ε 88Y γ - 89Zr syn 78.4 h ε 89Y β+ 89Y γ - 90Zr 51.45% stable 91Zr 11.22% stable 92Zr 17.15% stable 93Zr trace 1.53×106 y β− 93Nb 94Zr 17.38% >1.1×1017 y (β−β−) 94Mo 96Zr 2.8% 2.0×1019 y β−β− 96Mo
Decay modes in parentheses are predictit, but hae nae yet been observed