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52TeTellurium127.60

Metalloid

Tellurium (Te)

“Rarer in the crust than gold — yet a trace of it on your skin buys weeks of garlic-scented breath.”

View group 16 →View period 5 →

Atomic number52

Atomic mass127.60

Group16

Period5

BlockP-block

PhaseSolid

Electron structure

How its electrons are arranged

[Kr] 4d¹⁰ 5s² 5p⁴

Shell 1

2e⁻

Shell 2

8e⁻

Shell 3

18e⁻

Shell 4

18e⁻

Shell 5

6e⁻

Computed from the aufbau principle, with known real-world exceptions applied automatically.

🎯 Exam focus

Questions to practise

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1What was “problem gold” in 1780s Transylvania, and which two scientists finally established and named tellurium from it?

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2How do cadmium telluride thin-film panels turn sunshine into some of the cheapest solar electricity on record?

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3Name two household items that quietly depend on tellurium — think of the disc you once burned songs onto, and the compressor-free car fridge.

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4Explain the strange garlic-breath effect by which tellurium exposure betrays itself in the human body.

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5Write tellurium’s electron configuration, count its valence electrons, and settle its group, period and block.

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6Klaproth named one element for the sky and this one for the Earth — name both elements and explain the Roman myth behind the pairing.

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The notes

About the element

Characteristics

A brittle, silvery-white, semiconducting metalloid; configuration [Kr] 4d¹⁰ 5s² 5p⁴ places it in Group 16 (the oxygen family), Period 5, p-block, with six valence electrons.
Among the rarest stable elements in the crust — rarer than gold — yet recovered in tonne lots as a byproduct of copper and lead refining.
The body mistakes traces of it for sulfur: volatile dimethyl telluride lends the breath a garlic smell that can linger for weeks.
It can actually take electrons from metals, forming telluride anions (Te²⁻) and ionic salts — a shade more “metallic” than its cousin selenium.

Appearance

A brittle, silvery-white metalloid with a metallic gleam, usually sold as small rods or a crystalline powder. It is one of the rarest stable elements in Earth’s crust and is handled with care, for its dust is toxic.

Real world

Where you meet it

✦ Uses

Cadmium telluride (CdTe) thin-film solar panels — among the cheapest solar electricity ever generated, born on tellurium-coated glass.
Bismuth telluride (Bi₂Te₃) thermoelectric modules that chill car fridges and picnic coolers, and turn waste heat back into power.
The rewritable layer of DVDs and Blu-ray discs: a germanium-antimony-tellurium (GeSbTe) alloy flickering between glassy and crystalline states.
A pinch of tellurium in steel and copper makes the metal cut like butter on lathes, sharply improving machinability.

◍ Everyday examples

A solar farm’s dark, glassy panels may be cadmium telluride thin-film rather than everyday silicon.
A compressor-free 12-volt car fridge cools its drinks on a bismuth telluride Peltier plate.
A rewritable CD or DVD in a family drawer stores its data in a nanometre film of GeSbTe.

Story

History & name

In 1782 the Austrian mining official Franz-Joseph Müller von Reichenstein was puzzling over a pale ore from Transylvania that looked exactly like gold but yielded none — miners called it “problem gold”. From it he extracted a new, brittle, silvery element, sending samples to Sweden’s great chemist Torbern Bergman, who confirmed the novelty but died before finishing the study. In 1798 Martin Klaproth completed the investigation and named the element tellurium, from the Latin tellus, “Earth” — a fitting companion to his earlier uranium, named for the sky.

Name originLatin tellus, “Earth”, bestowed by Martin Klaproth in 1798.