Zirconium

Zirconium,  ₄₀Zr

General properties
Name, seembol	zirconium, Zr
Appearance	sillery white
Pronunciation	/zərˈkoʊniəm/ zər-KOH-ni-əm
Zirconium in the periodic cairt
Ti ↑ Zr ↓ Hf yttrium ← zirconium → niobium
Atomic nummer (Z)	40
Group, block	group 4, d-block
Period	period 5
Element category	transeetion metal
Staundart atomic wicht (Ar)	91.224
Electron configuration	[Kr] 5s2 4d2
per shell	2, 8, 18, 10, 2
Pheesical properties
Phase	solid
Meltin pynt	2128 K ​(1855 °C, ​3371 °F)
Boilin 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 of fusion	14 kJ/mol
Heat o	573 kJ/mol
Molar heat capacity	25.36 J/(mol·K)
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
Miscellanea
Crystal 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
Bulk 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
Discovery	Martin Heinrich Klaproth (1789)
First isolation	Jöns Jakob Berzelius (1824)
Maist stable isotopes o zirconium
iso NA hauf-life DM DE (MeV) DP 88Zr syn 83.4 d ε - 88Y γ 0.392D - 89Zr syn 78.4 h ε - 89Y β+ 0.902 89Y γ 0.909D - 90Zr 51.45% 90Zr is stable wi 50 neutrons 91Zr 11.22% 91Zr is stable wi 51 neutrons 92Zr 17.15% 92Zr is stable wi 52 neutrons 93Zr trace 1.53×106 y β− 0.060 93Nb 94Zr 17.38% >1.1×1017 y (β−β−) 1.144 94Mo 96Zr 2.8% 2.0×1019 y β−β− 3.348 96Mo
Decay modes in parentheses are predictit, but hae nae yet been observed

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 such as zirconium dioxide an zirconocene dichloride, respectively. Five isotopes occur naiturally, three o which are stable. Zirconium compoonds hae na kent biological role.