What is the atomic number of tellurium

Tellurium

Tellurium: characteristics

Atomic number:

52

Symbol:

Te

Name (German):

Tellurium

Name (English):

Tellurium (official name according to IUPAC)

Group:

Chalcogens

IUPAC group:

16 (old nomenclature: Group VI A)

Period:

5

Dimensions (rounded):

127.6 u (rounded to the five significant digits)

Dimensions (exact):

127.6 u +/- 3 digit (s) [1]

Discoverer:

from Reichenstein

Discovery year:

1782

Occurrence:

Naturally

Frequency:

1,00 · 10-6 % (percentage by mass of the earth's shell, i.e. the earth's crust / oceans up to 16 km depth)

CAS number [2]:

22541-49-7

Tellurium: atomic properties

Atomic radius (empirical):

140 pm

Atomic radius (calculated):

123 pm

Covalent radius:

135 pm

Van der Waals radius:

206 pm

Atomic volume:

20.50 cm3/ mol

Ionization energies:

kJ / moleV
1.869.3 kJ / mol9.010 eV
2.1790 kJ / mol18.552 eV
3.2698 kJ / mol27.963 eV
4.3610 kJ / mol37.415 eV
5.5668 kJ / mol58.745 eV
6.6820 kJ / mol70.684 eV
7.13200 kJ / mol136.808 eV

Oxidation numbers:

VI, IV, -II
(most important highlighted in bold)

Electronegativity (Pauling):

2,1

Electronegativity (Allred / Rochow):

2

Ionic radius:

221 pm

Grid energy:

2 eV / particle

Number nat. Isotopes:

8

Number of stable isotopes:

7

Number of unstable isotopes:

15

Stable isotopes:

isotopefrequency
120Te0,096%
122Te2,60%
123Te0,908%
124Te4,816%
125Te7,14%
126Te18,95%
128Te31,69%
130Te33,80%

Radioactive isotopes:

isotopeHalf-life
127Te109d (i.e. days, from lt. this)

(The list contains only the most important isotope with a known half-life.)

Electron configuration:

[Kr] 4d105s25p4
OrbitalElectrons
1s2
2s2
2p6
3s2
3p6
3d10
4s2
4p6
4d10
4f0
5s2
5p4
5d0
5f0

Shell model:

  • 6 electrons in the outermost occupied shell
  • 18 electrons in the second to last occupied shell
  • 18 electrons in the occupied shell below

Tellurium: material properties

Melting point:

722.8 K (~ 449.65 ° C)

Boiling point:

1261 K (~ 987.85 ° C)

State of aggregation:

fixed (under normal conditions)

Crystal structure:

hexagonal

Metal properties:

Semi-metal

Specific heat of fusion:

17.49 kJ / mol

Specific heat of vaporization:

50.63 kJ / mol

Thermal conductivity:

2.35 W / m / K

Specific heat capacity:

0.202 J / gK

Specific density:

6.232 g / cm3
(under normal conditions)

Hardness (according to Mohs):

2,25

Expansion coefficient:

17,2 · 10-6/ K
(linear thermal expansion coefficient α)


 
Remarks:
  1. 1 digit = least significant digit, i.e. 2.435 +/- 3 digits means 2.432 ... 2.438
  2. The "CAS Registry Number" is that of the element Tellurium from Chemical Abstracts Service Assigned key number, which makes it easier to find specialist articles about this element in all publications and databases structured according to the CAS system.
    Legal notice: CAS registry number is a registered trademark of the American Chemical Society.