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Tellurium

Element 52 · Metalloid

Specimen

Atomic number
52
Atomic mass
127.6
State at room temperature
Solid
Melting point
449.5 °C
Boiling point
987.9 °C
Density
6.232 g/cm³
Discovered
1782

Atomic mass from IUPAC.1 Other physical data from PubChem.2

Can I eat it?

In food and water
Harmful. Food contains only traces of tellurium. Elemental tellurium has low toxicity in rats. Large amounts cause vomiting and a garlic smell on the breath. The RSC calls tellurium very toxic. 34

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The atom

Te
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 18
5 (O) outermost 6
Total52

Configuration [Kr] 4d¹⁰ 5s² 5p⁴

4d ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓
5s ↑ ↓
5p ↑ ↓ ↑ ↑
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 52 protons. The outermost shell is shown in red. Electrons do not travel on rings: they fill orbitals, regions where an electron is likely to be found. The boxes are those orbitals for the electrons outside the Kr core, with one arrow per electron.

Related elements

Group 16
O Oxygen S Sulfur Se Selenium Po Polonium Lv Livermorium

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Sources

  1. 1

    IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024. Abridged Standard Atomic Weights 2024 .

    The atomic mass shown for the 84 elements that have a standard atomic weight.

  2. 2

    National Center for Biotechnology Information (PubChem), 2026. Periodic Table of Elements .

    Electron configuration, melting and boiling points, density and discovery year for all 118 elements.

  3. 3

    Sári D, Ferroudj A, Semsey D, et al. (Nanomaterials), 2024. Tellurium and Nano-Tellurium: Medicine or Poison? .

    • Ingesting significant amounts of Te causes symptoms like vomiting, nausea, a metallic taste in the mouth ... and a distinctive garlic-like odor on the breath. ... In the case of elemental Te, the oral LD 50 is >5000
  4. 4

    Royal Society of Chemistry, 2026. Tellurium - Element information, properties and uses .

    • Tellurium has no known biological role. It is very toxic and teratogenic
  5. 5

    National Institute of Standards and Technology (NIST), 2026. Atomic Weights and Isotopic Compositions for All Elements .

    Isotopic composition of each element; the most abundant isotope sets the neutron count in the nucleus view.