52TeTellurium127.6

Tellurium is element 52, a metalloid in period 5, group 16 of the periodic table. At room temperature it is a solid.

Electron configuration [Kr] 4d10 5s2 5p4

Electrons per shell 2, 8, 18, 18, 6

Te

Tellurium data

Atomic number52
SymbolTe
Atomic mass127.6 u
CategoryMetalloid
Group16
Period5
Blockp
State at 25 °Csolid
Melting point723 K (449.9 °C)
Boiling point1261 K (987.9 °C)
Density6.24 g/cm³
Electronegativity (Pauling)2.1
Atomic radius135 pm
1st ionization energy869 kJ/mol
Electron affinity-190 kJ/mol
Oxidation states-2, +2, +4, +5, +6
Common ion charge2−
Discovered1782

Orbital diagram

Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.

Work through tellurium’s configuration and its ions →

Where tellurium sits

Tellurium belongs to the metalloids. Its Pauling electronegativity of 2.1 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.

Tellurium FAQ

What is the electron configuration of tellurium?

Tellurium (Z = 52) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4. In noble-gas shorthand that is [Kr] 4d10 5s2 5p4.

How many valence electrons does tellurium have?

6 (outer shell (n = 5)).

What is the atomic mass of tellurium?

The standard atomic weight of tellurium is 127.6 u, so one mole weighs 127.6 g.

Is tellurium a metal?

Tellurium is a metalloid: it has properties between metals and nonmetals.

What is the charge of a tellurium ion?

Tellurium most commonly forms Te2−.