Tellurium
A rare metalloid used in solar panels and thermoelectrics.
Inside the Tellurium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Tellurium atom step by step.
Electron configuration
[Kr] 4d10 5s2 5p4
A neutral Tellurium atom has 52 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 723 K (450 °C)
- Boiling point
- 1261 K (988 °C)
- Density
- 6.232 g/cm³
- Electronegativity
- 2.1 Pauling
- Atomic radius
- 140 pm
- 1st ionization energy
- 869 kJ/mol
- Category
- Metalloids
Discovery & naming
- Discovered
- 1782
- Discovered by
- Franz-Joseph Müller von Reichenstein
- Origin of name
- Latin 'tellus', meaning Earth.
Notable uses
Solar panels, thermoelectric devices, and alloys.
Where Tellurium comes from
Neutron star mergers
Largely an r-process element, built by rapid neutron capture in neutron-rich environments.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 52
- Atomic mass
- 127.60
- Category
- Metalloids
- Group · Period
- 16 · 5
- Block
- p-block
- Shells
- 2 · 8 · 18 · 18 · 6