Term: thallium (Tl)
Literally meaning: “pertaining to green young shoot ”
Origin: Anc Greek
θαλλός/thallos(=young shoot, green branch, twig) > θρέφω/threpho(=feed)
The element named because of the bright green line in its spectrum
The element was found and named by Sir William Crookes (1832-1919) and independently by Claude-Auguste Lamy in 1861. Thallium used to poison rodents but nowadays it is prohibited.
William Crookes, On the Existence of a New Element, probably of the Sulphur Group, The Chemical News, vol III, No 69, March 30, 1861
John Emsley, The Trouble with Thallium, New Scientist, vol 79 No 1115, 10 August 1978, p 392.
Thallium is a chemical element with atomic number 81 and atomic mass 204.3833. Its oxide is used to make glass that has a high index of refraction.