Tellurium
Tellurium (Te, atomic number 52) is a Period 5 metalloid (p-block, 127.6 u). Chalcogen metalloid rarer in Earth's crust than platinum due to volatile hydride loss during planetary accretion; forms high-efficiency cadmium telluride (CdTe) thin-film so
Tellurium is a chemical element on the periodic table with the atomic symbol Te, atomic number 52, and standard atomic weight 127.6 u. Classified as a Metalloid within Group 16 and Period 5 (p-block), tellurium possesses a ground-state electron configuration of [Kr] 4d10 5s2 5p4 distributed across 5 concentric Bohr electron shells (2 · 8 · 18 · 18 · 6) with 6 outer-shell electrons. Chalcogen metalloid rarer in Earth's crust than platinum due to volatile hydride loss during planetary accretion; forms high-efficiency cadmium telluride (CdTe) thin-film solar photovoltaics.
⚛️ Interactive Periodic Table Lab: Explore Tellurium (Te, Z = 52) in the CRV Science Dynamic Periodic Table & Bohr Orbital Lab to visualize its animated 2 · 8 · 18 · 18 · 6 electron shells, simulate live phase transitions from 0 K to 6,000 K, and compare periodic heatmaps across all 118 IUPAC elements.
Atomic Structure and Periodic Trends: How Do Quantum Orbitals Define Tellurium?
Electron Shell Architecture and Ground-State Configuration
A neutral atom of tellurium contains 52 protons in its atomic nucleus balanced by 52 electrons occupying quantized atomic orbitals. In the Bohr-Sommerfeld and quantum-mechanical orbital models, these electrons populate 5 principal energy shells (K (n=1): 2e−, L (n=2): 8e−, M (n=3): 18e−, N (n=4): 18e−, O (n=5): 6e−), terminating in the directional dumbbell-shaped p-orbital (azimuthal quantum number l = 1) with ground-state configuration [Kr] 4d10 5s2 5p4. Removing the most loosely bound valence electron from an isolated gaseous tellurium atom requires a first ionization energy of 869 kJ/mol, while its tendency to attract shared bonding electrons is quantified by a Pauling electronegativity of 2.10.
Periodic Table Position and Neighboring Elements
Within the periodic table, Tellurium occupies Period 5, Group 16 of the p-block (Metalloids). Along Period 5, it is flanked by Antimony (Sb, Z = 51) and Iodine (I, Z = 53). Vertically within its periodic family, Tellurium shares valence orbital symmetry and homologous chemical trends with Oxygen (O), Sulfur (S), Selenium (Se), Polonium (Po). Learners can interactively compare Tellurium's orbital radii, ionization energy, and Pauling electronegativity against all neighboring elements in the Dynamic Periodic Table Lab.
Physical and Thermodynamic Properties: How Does Tellurium Behave Across Temperature Regimes?
Standard Phase, Melting Point, and Boiling Point Dynamics
At standard ambient temperature and pressure (298.15 K / 25 °C, 1 atm), elemental tellurium exists as a crystalline solid. As thermal energy increases, its crystal or molecular lattice undergoes solid-to-liquid fusion at a melting point of 722.66 K (+449.51 °C / +841.1 °F) and transitions to the vapor phase at a normal boiling point of 1,261 K (+987.85 °C / +1810.1 °F), spanning a liquid thermodynamic range of 538.34 K. In the CRV Science Dynamic Periodic Table, dragging the live temperature slider between absolute zero (0 K) and solar-photosphere temperatures (6,000 K) dynamically tracks Tellurium's state transitions in real time alongside enthalpy and entropy phase equilibria.
Quantitative Atomic and Thermodynamic Parameter Matrix
| Parameter | Quantitative Value / Formula | Physical / Quantum Basis | Comparative Context in Group 16 / Period 5 |
|---|---|---|---|
| Atomic Number & Symbol | Z = 52 (Te) | 52 nuclear protons; nuclear charge +52e | Located in Period 5, Group 16 (p-block) |
| Standard Atomic Weight | 127.6 u (g/mol) | Abundance-weighted isotopic nucleon mass | ~76 neutrons in dominant/reference mass number |
| Electron Configuration | [Kr] 4d10 5s2 5p4 | Shells: 2 · 8 · 18 · 18 · 6 (6 outer-shell e−) | Metalloids valence orbital architecture |
| Electronegativity & Ionization | χ = 2.10; IE1 = 869 kJ/mol | Pauling bond polarity scale & first valence ionization enthalpy | Governs covalent vs. ionic bond character |
| Melting & Boiling Points | MP: 722.66 K; BP: 1261 K | Cohesive lattice energy and intermolecular forces | STP (298 K) phase: SOLID (Liquid range: 538.34 K) |
| Principal Oxidation States | +4, +6, -2 | Valence electron donation, sharing, or acceptance | Discovered / First Isolated: 1782 |
Chemical Reactivity, Bonding, and Oxidation States: How Does Tellurium Form Compounds?
Characteristic Oxidation States and Coordination Chemistry
As a p-block metalloid straddling the amphoteric staircase between metals and nonmetals, it exhibits intermediate ionization energy and electronegativity, forming directional covalent networks with semiconducting electronic bandgaps. In chemical compounds, tellurium exhibits characteristic oxidation states of +4, +6, -2. Depending on the electronegativity difference (Δχ) of its bonding partners—such as Oxygen (χ = 3.44), Fluorine (χ = 3.98), Chlorine (χ = 3.16), Nitrogen (χ = 3.04), Carbon (χ = 2.55), or Hydrogen (χ = 2.20)—tellurium forms redox-specific oxides, halides, hydrides, or coordination complexes governed by Gibbs free energy (ΔG = ΔH − TΔS).
Nucleosynthesis, Discovery History, and Elemental Origins
First identified or isolated in 1782, Tellurium carries a distinct cosmological and geochemical signature. With atomic number Z = 52 beyond the iron-56 binding-energy peak, tellurium is synthesized astrophysically via neutron-capture nucleosynthesis—combining slow neutron capture (the s-process in asymptotic giant branch stars) and rapid neutron capture (the r-process in neutron-star mergers and core-collapse supernovae).
Biological Role and Scientific Applications: Why Is Tellurium Important in Nature and Technology?
Biochemical Classification: Abiotic / Technological / Synthetic
In comparative biochemistry and systems physiology, Tellurium is classified as Abiotic / Technological / Synthetic. No known essential biological role; important in planetary geochemistry, astrophysics, materials science, or nuclear physics. Across terrestrial and marine ecosystems, its chemical speciation interacts with thermodynamics, enthalpy, entropy, chemistry.
Key Mechanistic Functions and Technological Uses
Chalcogen metalloid rarer in Earth's crust than platinum due to volatile hydride loss during planetary accretion; forms high-efficiency cadmium telluride (CdTe) thin-film solar photovoltaics. Researchers and students can further investigate Tellurium's functional role alongside all 118 elements by launching the Interactive Periodic Table & Element Detective Lab on CRV Science Learn.
Frequently Asked Scientific Questions
What is the electron configuration and valence shell structure of Tellurium (Te)?
Tellurium (atomic number Z = 52) has the ground-state electron configuration [Kr] 4d10 5s2 5p4, distributing its 52 electrons across 5 shells as 2 · 8 · 18 · 18 · 6. Its outermost shell contains 6 electrons, placing Tellurium in Group 16, Period 5 (p-block) as a member of the Metalloids. You can watch these 52 electrons orbit the nucleus in real time in the Dynamic Periodic Table Bohr Lab.
What phase of matter is Tellurium at room temperature, and when does it melt or boil?
At standard room temperature (298 K / 25 °C) and 1 atm pressure, Tellurium is a crystalline solid. It melts at 722.66 K (+449.51 °C / +841.1 °F) and boils at 1,261 K (+987.85 °C / +1810.1 °F). Using the 0–6,000 K temperature slider in the Interactive Periodic Table, you can observe Tellurium's exact solid, liquid, and gas transitions relative to all other elements.
How does Tellurium function in biochemistry, materials science, and technology?
Chalcogen metalloid rarer in Earth's crust than platinum due to volatile hydride loss during planetary accretion; forms high-efficiency cadmium telluride (CdTe) thin-film solar photovoltaics. In biological systems, it is categorized under Abiotic / Technological / Synthetic, with principal oxidation states of +4, +6, -2 and a first ionization energy of 869 kJ/mol.