INTRODUCTION
Iridium is a white, brittle, extremely hard, metallic element. It is extremely inert chemically, resisting even the action of aqua regia. In its chemical compounds it forms tetravalent and trivalent salts.
Its specific gravity is 22.6, making it more than twice as dense as lead. Iridium and osmium are together considered to be the densest elements; their densities are so close as to be nearly indistinguishable.
BASIC INFORMATIONS
- Atomic Number
- 77
- Atomic Mass
- 192.217
- Atomic radius
- 0.126
- Ionization energy
- 900
- Electronic config
- 2,8,18,32,15,2
- Principal Valency
- +2
- Density g/cm³
- 22.61
- Melting point °C
- 2466
- Boiling point °C
- 4428
- Type of Element
- Metal
- Electronegativity
- 2.2
- Element Category
- Cobalt Group
- Appearance
- White solid
- Block
- d-block
- Period
- 6
- Group
- 9
- No of Isotopes
- 26
- Occurrence
- Alloy deposit
- Abundance in ppm
- 0.001
- Year of Discovery
- 1803
EXTRACTION
It is obtained as a by-product of nickel production.
OXIDATION STATES
-3,-1,0,+1,+2,+3,+4,+5,+6 (Weakly basic)
MAJOR SOURCE
Platiniridium, Osmiridium
EXAMPLES OF COMPOUND PRESENT
Iridium Oxide
ECONOMIC IMPORTANCE
* Platinum iridium alloy are used in making precision instruments, surgical tools, pen points, and standard weights and lengths.
* Iridium is used mostly as an alloying material for platinum; the alloy, which is used to make the electrodes for long life sparkling plug.
* Iridium is used to make very hard alloys which are used to make pivots for instruments.
