Atomic number: 52

Symbol: Te

Category: metalloid

Density at 25°C: solid:  6.24 g·cm−3

Tellurium is one of the rarest metalloids on the earth's crust, though on a cosmic scale it is quite common. It tends to be found combined with other minerals and elements.  Tellurium is often used in a other metals to produce alloys to help improve machining.

Tellurium crystal. image: adapted from wikipedia

Use, natural applications or common combinations: 

  • Solar cells
  • Optical glass fibres

Basic characteristics:

  • Standard atomic weight: 127.60(3)
  • Melting point:  449.51 °C
  • Boiling point: 988 °C
  • Radioactivity: almost all naturally stable. a few radioactive 120Te, 128Te and 130Te but very long half lives.