The name is derived from the Latin word ‘tellus’, meaning earth. It was discovered in 1782. It is heavier than Iodum although it has a lower atomic number. It has some metallic and some non-metallic properties. It is quite similar to Selenium.
It is used together with Selenium and Bismuth to make tiny refrigeration units based on thermo electric effects. Other uses are: radio detectors, silver alloys to retain shine, disinfectants. colouring of silver bromide in photography and semi conductors. It increases the electrical and heat conductivity when it is combined with other metals. It is also used as a catalyst in the vulcanisation of rubber.