Zirconium was discovered by Martin Heinrich Klaproth in 1789. It was first isolated in 1824 by Jons Jakob Berzelius by heating a mixture of potassium and potassium zirconium fluoride in an iron tube.
Atomic number: 40
Atomic weight: 91.224
Group, period, block: 4, 5, d
Color: silvery white
Classification: transition metal
Electron configuration: 5s2 4d2
Density: 6.52 g/cm-3
Melting point: 2128 K,1855 °C,3371 °F
Boiling point: 4682 K,4409 °C,7968 °F
Oxidation states: 4, 3, 2, 1
Electronegativity: 1.33 (Pauling scale)
Ionization energies: 1st: 640.1 kJ·mol-1
Covalent radius: 175±7 pm
Van der Waals radius: no data
There are five naturally occurring isotopes of zirconium exist, 90Zr, 91Zr, 92Zr, 94Zr, and 96Zr.