INTRODUCTION
Tellurium is a silver-white, brittle, semimetallic element.It is comparatively stable element, insoluble in water and hydrochloric acid but soluble in nitric acid and aqua regia.
It is quite rare and ranks about 78th in natural abundance among the elements in Earth's crust.Tellurium occurs in the pure state or is found in combination with gold, silver, copper, lead, and nickel in such minerals as sylvanite, petzite, and tetradymite.
BASIC INFORMATIONS
- Atomic Number
- 52
- Atomic Mass
- 127.6
- Atomic radius
- 0.137
- Ionization energy
- 869
- Electronic config
- 2,8,18,18,6
- Principal Valency
- -2
- Density g/cm³
- 6.25
- Melting point °C
- 449.51
- Boiling point °C
- 988
- Type of Element
- Metalloid
- Electronegativity
- 2.1
- Element Category
- Chalcogen
- Appearance
- Silvery white solid
- Block
- p-block
- Period
- 5
- Group
- 16
- No of Isotopes
- 38
- Occurrence
- Free and combine
- Abundance in ppm
- 0.001
- Year of Discovery
- 1782
EXTRACTION
Reduction of telluric oxide
OXIDATION STATES
+6,+5,+4,+2,-2 (Mildly acidic)
MAJOR SOURCE
Sylvanite, Petzite, Tetradymite
EXAMPLES OF COMPOUND PRESENT
Tellurium dioxide, Sodium telluride
ECONOMIC IMPORTANCE
* Tellurium is highly used in the manufacture of rectifiers and thermoelectric devices and in semiconductor research.
* Accompany with other organic substances, it is employed as a vulcanizing agent in the processing of natural and synthetic rubber.
* Colloidal tellurium is an an active germicide, insecticide, and fungicide.
* It is used to impart a blue colour to glass and in antiknock compounds for gasoline.
