Tellurium (Te)

Tellurium properties

Atomic number

52

Atomic mass

127.6 u

Category

Metalloid

Group

16

Period

5

Block

p-block

State at room temp.

Solid

Electronegativity

2.1

Melting point

722.66 K (449.5 °C)

Boiling point

1,261 K (987.8 °C)

Density

6.24 g/cm³

Valence electrons

6

Common charges

−2

Oxidation states

+6, +4, −2

Atomic radius

206 pm

Ionization energy

9.01 eV

Electron affinity

1.971 eV

Radioactive

No, has stable isotopes

Discovered

1782

Tellurium electron configuration

The electron configuration of Tellurium (Te) is [Kr] 4d10 5s2 5p4. Its 52 electrons are arranged in shells as 2, 8, 18, 18, 6.

Protons, neutrons and electrons in Tellurium

A neutral Tellurium atom has 52 protons and 52 electrons. Most Tellurium atoms have about 76 neutrons: the atomic mass rounded to 128, minus the atomic number 52.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Tellurium have?

6

Tellurium has 6 valence electrons in its outermost shell, shell 5. These are the electrons involved in chemical bonding.

See every element: Periodic table with valence electrons

Tellurium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Tellurium

127.6 g/mol

One mole of Tellurium atoms (6.022 × 10²³ atoms) has a mass of 127.6 grams. Use this value to convert between grams and moles.

Tellurium facts

• People exposed to even small amounts of tellurium can develop 'tellurium breath', a strong garlic-like odor.
• Tellurium is one of the few elements that combines with gold in nature, forming gold telluride minerals such as calaverite.
• Tellurium (Te) has atomic number 52 and is a solid at room temperature. It was discovered in 1782.

Position in the periodic table

Tellurium is element 52, in period 5 and group 16 of the periodic table, in the p-block.

All metalloids

Uses of Tellurium

Tellurium's largest modern use is in cadmium telluride solar panels. Bismuth telluride is used in thermoelectric devices, which can turn an electric current into cooling or a temperature difference into electricity. Small amounts of tellurium make steel and copper easier to machine, and tellurium compounds help vulcanize rubber and form the phase-change layers in rewritable optical discs.

Who discovered Tellurium?

Austrian mineralogist Franz-Joseph Müller von Reichenstein discovered tellurium in 1782 in gold ore from Transylvania. German chemist Martin Heinrich Klaproth confirmed it in 1798 and named it after tellus, the Latin word for Earth.

Where does the name come from?

Tellurium comes from the Latin tellus, meaning 'earth'. Martin Heinrich Klaproth chose the name in 1798 after confirming the element, which Franz-Joseph Müller von Reichenstein had discovered in a gold ore in 1782.

Discovery timeline