tellurium

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

Crystalline tellurium has a silvery-white appearance, and exhibits a metallic lustre when pure. It is brittle and easily pulverised. Tellurium is a p-type semiconductor, and shows varying conductivity with crystal alignment. Its conductivity increases slightly with exposure to light. It can be doped with silver, copper, gold, tin, or other elements.

Humans exposed to as little as 0.01 mg m^-3 in air, or less, develop "tellurium breath", which has a garlic-like odour.

General information

Discoveror: Franz Joseph Muller von Reichstein
Date discovered: 1783
Discovered at: Romania
Meaning of name: From the Latin word "tellus" meaning "earth"

Physical data

Standard state: solid at 298 K
Colour: silvery lustrous grey
Density of solid at ambient temperature/kg m^-3: 6240
Molar volume/cm³: 20.46

Radii /pm

Atomic: 123
Covalent (single bond):
Pauling radius for the ion [Te]^-: 250

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	100.4	116.9	42.8	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 2.1
Allred Rochow: 2.01

Crystal Structure

structure: trigonal

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 722.66
boiling point: 1261

Enthalpies /kJ mol^-1

fusion: 17.5
vaporization: 48

single bond enthalpies:

Te-F	Te-Cl	Te-Br	Te-I	Te-Te
330	311	176	121	259.8

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	869.3
2nd	1790
3rd	2698
4th	3610
5th	5668
6th	6820
7th	13200

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
120Te	119.904048 (21)	0.096 (2)
122Te	121.903050 (3)	2.60 (4)
123Te	122.9042710 (22)	0.908 (2)
124Te	123.9028180 (18)	4.816 (6)
125Te	124.9044285 (25)	7.14 (6)
126Te	125.9033095 (25)	18.95 (1)
128Te	127.904463 (4)	31.69 (1)
130Te	129.906229 (5)	33.80 (1)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW