Page 53 - Curriculum Visions Dynamic Book

Zirconium (Zr)
Element 40. A soft, silvery-white metal belonging to the transition metals in the Periodic Table. Zirconium powder can catch fire (combust) spontaneously in air. Zirconium resists attack by acids and alkalis.An alloy of zirconium
and zinc is magnetic at very low temperatures.
Discovery
Zirconium was identified in 1789 in the mineral zircon by the German chemist Martin Heinrich Klaproth. It was isolated as an element in 1824 by the Swedish chemist Jöns Jacob Berzelius.
Technology
Crystals of zirconium oxide appear in jewellery as a substitute for diamond, where it is known as cubic zirconium.
It is also used as a structural material
for nuclear reactors, because it is highly transparent to neutrons, and as an alloy with magnesium and steel. Since it resists corrosion, it is widely applied in the chemical and power industries. It is also used for surgical implants. Zirconium is a superconductor at low temperatures.
It is used in the form of a zirconium– niobium alloy. Zirconium is used to make bulb filaments.
Geology
Zirconium is not found as a native element. It occurs in the mineral zircon (ZrSiO4), which is gold coloured.
Biology
Zirconium is not found in living things.
Crystal of zircon
Zn see Zinc; Zr see Zironium
Key facts...
Name: zirconium
Symbol: Zr
Atomic number: 40
Atomic weight: 91.22
Position in Periodic Table: transition metal,
group (4) (titanium group); period 5 State at room temperature: solid Colour: silvery-white
Density of solid: 6.49 g/cc
Melting point: 1,852°C
Boiling point: 4,377°C
Origin of name: from the Arabic word zargun,
meaning gold colour, referring to the colour
of the mineral zircon
Shell pattern of electrons: 2–8–18–10–2
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