All practice pages/Interatomic theory/Elements
Element 40, a transition metal
The metal neutrons pass straight through, which is why it wraps the fuel in nuclear reactors, and the stuff of cubic zirconia gems.
Period 5, group 4. The other transition metals are tinted, and every cell opens its own article.
Like other transition metals, zirconium loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.
Mined as zircon (ZrSiO₄) from beach sands, above all in Australia and South Africa. Zircon crystals are among the oldest things on Earth: grains from Western Australia are about 4.4 billion years old.
Martin Heinrich Klaproth identified zirconia in 1789 in a zircon gem from Sri Lanka, and Jöns Jacob Berzelius isolated the metal in 1824. The name comes from the mineral zircon, probably from the Persian zargun, gold-colored.
Most zircon goes into ceramics, tiles and foundry molds. The metal, alloyed as Zircaloy, sheathes the uranium fuel in nuclear reactors because it barely absorbs neutrons and resists corrosion. Zirconium dioxide makes cubic zirconia gems, ceramic knives and dental crowns.