Te Tellurium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

Tellurium is a chemical element with symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white Metalloid. Tellurium is chemically related to selenium and sulfur.
It belongs to group 16 of the periodic table having trivial name chalcogens.
Tellurium Facts
Read key information and facts about element Tellurium
Name | Tellurium |
Atomic Number | 52 |
Atomic Symbol | Te |
Atomic Weight | 127.6 |
Phase | Solid |
Color | Silver |
Appearance | - |
Classification | Metalloid |
Group in Periodic Table | 16 |
Group Name | oxygen family |
Period in Periodic Table | period 5 |
Block in Periodic Table | p -block |
Electronic Configuration | [Kr] 4d10 5s2 5p4 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 18, 6 |
Melting Point | 722.66 K |
Boiling Point | 1261 K |
CAS Number | CAS13494-80-9 |
How to Locate Tellurium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 52 to find Tellurium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Tellurium on periodic table look for cross section of group 16 and period 5 in the modern periodic table.
Tellurium History
The element Tellurium was discovered by F.-J.M. von Reichenstein in year 1782 in Romania. Tellurium was first isolated by H. Klaproth in . Tellurium derived its name from Latin tellus, meaning 'earth'.
Muller observed it as an impurity in gold ores from Transylvania.
Tellurium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Tellurium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
---|---|---|
Abundance in Universe | 9 | 0.09 |
Abundance in Sun | - | - |
Abundance in Meteorites | 2100 | 300 |
Abundance in Earth's Crust | 1.0 | 0.2 |
Abundance in Oceans | - | - |
Abundance in Humans | - | - |
Crystal Structure of Tellurium
The solid state structure of Tellurium is Simple Trigonal.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
a | b | c |
---|---|---|
445.72 pm | 445.72 pm | 592.9 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
π/2 | π/2 | 2 π/3 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
Space Group Name | P3121 | ![]() |
Oxidation States | Space Group Number | 152 |
Crystal Structure | Simple Trigonal |
Tellurium Atomic and Orbital Properties
Tellurium atoms have 52 electrons and the electronic shell structure is [2, 8, 18, 18, 6] with Atomic Term Symbol (Quantum Numbers) 3P2.
Atomic Number | 52 |
Number of Electrons (with no charge) | 52 |
Number of Protons | 52 |
Mass Number | 128 |
Number of Neutrons | 76 |
Shell structure (Electrons per energy level) | 2, 8, 18, 18, 6 |
Electron Configuration | [Kr] 4d10 5s2 5p4 |
Valence Electrons | 5s2 5p4 |
Valence (Valency) | 6 |
Main Oxidation States | -2, 2, 4, 6 |
Oxidation States | -2, -1, 0, 1, 2, 3, 4, 5, 6 |
Atomic Term Symbol (Quantum Numbers) | 3P2 |
Bohr Atomic Model of Tellurium - Electrons per energy level

n | s | p | d | f |
---|
Ground State Electronic Configuration of Tellurium - neutral Tellurium atom
Abbreviated electronic configuration of Tellurium
The ground state abbreviated electronic configuration of Neutral Tellurium atom is [Kr] 4d10 5s2 5p4. The portion of Tellurium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 5s2 5p4, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Tellurium
Complete ground state electronic configuration for the Tellurium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

Atomic Structure of Tellurium
Tellurium atomic radius is 123 pm, while it's covalent radius is 135 pm.
Atomic Radius Calculated | 123 pm (1.23 Å) |
Atomic Radius Empirical | 140 pm (1.4 Å) |
Atomic Volume | 20.449 cm3/mol |
Covalent Radius | 135 pm (1.35 Å) |
Van der Waals Radius | 206 pm |
Neutron Cross Section | 5.4 |
Neutron Mass Absorption | 0.0013 |
Atomic Spectrum of Tellurium
Tellurium Chemical Properties: Tellurium Ionization Energies and electron affinity
The electron affinity of Tellurium is 190.2 kJ/mol.
Valence | 6 |
Electronegativity | 2.1 |
ElectronAffinity | 190.2 kJ/mol |
Ionization Energy of Tellurium
Refer to table below for Ionization energies of Tellurium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 869.3 |
2nd | 1790 |
3rd | 2698 |
4th | 3610 |
5th | 5668 |
6th | 6820 |
7th | 13200 |
Tellurium Physical Properties
Refer to below table for Tellurium Physical Properties
Density | 6.24 g/cm3(when liquid at m.p density is $5.7 g/cm3) |
Molar Volume | 20.449 cm3/mol |
Elastic Properties
Young Modulus | 43 |
Shear Modulus | 16 GPa |
Bulk Modulus | 65 GPa |
Poisson Ratio | - |
Hardness of Tellurium - Tests to Measure of Hardness of Element
Mohs Hardness | 2.25 MPa |
Vickers Hardness | - |
Brinell Hardness | 180 MPa |
Tellurium Electrical Properties
Tellurium is Conductor of electricity. Refer to table below for the Electrical properties ofTellurium
Electrical Conductivity | 10000 S/m |
Resistivity | 0.0001 m Ω |
Superconducting Point | - |
Tellurium Heat and Conduction Properties
Thermal Conductivity | 3 W/(m K) |
Thermal Expansion | - |
Tellurium Magnetic Properties
Magnetic Type | Diamagnetic |
Curie Point | - |
Mass Magnetic Susceptibility | -3.9e-9 m3/kg |
Molar Magnetic Susceptibility | -4.98e-10 m3/mol |
Volume Magnetic Susceptibility | -0.0000243 |
Optical Properties of Tellurium
Refractive Index | 1.000991 |
Acoustic Properties of Tellurium
Speed of Sound | 2610 m/s |
Tellurium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Tellurium
Melting Point | 722.66 K (449.51°C, 841.118 °F) |
Boiling Point | 1261 K (987.85°C, 1810.1299999999999 °F) |
Critical Temperature | - |
Superconducting Point | - |
Enthalpies of Tellurium
Heat of Fusion | 17.5 kJ/mol |
Heat of Vaporization | 48 kJ/mol |
Heat of Combustion | - |
Tellurium Isotopes - Nuclear Properties of Tellurium
Tellurium has 38 isotopes, with between 105 and 142 nucleons. Tellurium has 5 stable naturally occuring isotopes.
Isotopes of Tellurium - Naturally occurring stable Isotopes: 120Te, 122Te, 124Te, 125Te, 126Te.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
105Te | 52 | 53 | 105 | Synthetic | ||
106Te | 52 | 54 | 106 | Synthetic | ||
107Te | 52 | 55 | 107 | Synthetic | ||
108Te | 52 | 56 | 108 | Synthetic | ||
109Te | 52 | 57 | 109 | Synthetic | ||
110Te | 52 | 58 | 110 | Synthetic | ||
111Te | 52 | 59 | 111 | Synthetic | ||
112Te | 52 | 60 | 112 | Synthetic | ||
113Te | 52 | 61 | 113 | Synthetic | ||
114Te | 52 | 62 | 114 | Synthetic | ||
115Te | 52 | 63 | 115 | Synthetic | ||
116Te | 52 | 64 | 116 | Synthetic | ||
117Te | 52 | 65 | 117 | Synthetic | ||
118Te | 52 | 66 | 118 | Synthetic | ||
119Te | 52 | 67 | 119 | Synthetic | ||
120Te | 52 | 68 | 120 | 0.09% | Stable | N/A |
121Te | 52 | 69 | 121 | Synthetic | ||
122Te | 52 | 70 | 122 | 2.55% | Stable | N/A |
123Te | 52 | 71 | 123 | 0.89% | Stable | N/A |
124Te | 52 | 72 | 124 | 4.74% | Stable | N/A |
125Te | 52 | 73 | 125 | 7.07% | Stable | N/A |
126Te | 52 | 74 | 126 | 18.84% | Stable | N/A |
127Te | 52 | 75 | 127 | Synthetic | ||
128Te | 52 | 76 | 128 | 31.74% | Stable | |
129Te | 52 | 77 | 129 | Synthetic | ||
130Te | 52 | 78 | 130 | 34.08% | Stable | N/A |
131Te | 52 | 79 | 131 | Synthetic | ||
132Te | 52 | 80 | 132 | Synthetic | ||
133Te | 52 | 81 | 133 | Synthetic | ||
134Te | 52 | 82 | 134 | Synthetic | ||
135Te | 52 | 83 | 135 | Synthetic | ||
136Te | 52 | 84 | 136 | Synthetic | ||
137Te | 52 | 85 | 137 | Synthetic | ||
138Te | 52 | 86 | 138 | Synthetic | ||
139Te | 52 | 87 | 139 | Synthetic | ||
140Te | 52 | 88 | 140 | Synthetic | ||
141Te | 52 | 89 | 141 | Synthetic | ||
142Te | 52 | 90 | 142 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS13494-80-9 |
RTECS Number | RTECSWY2625000 |
CID Number | CID6327182 |
Gmelin Number | - |
NSC Number | - |