Symbol	Tl	Atomic radius: pm	170	Fusion: kJ/Mole	4.14
Name	Thallium	Ionic radius: pm	(+1)159	Boiling point: °C	1473
Atomic number	81	Electron affinity	0.36	Melting point: °C	304
Atomic weight	204.4	1st  ion potential	6.11	Specific Heat Cap: J/(g K)	0.13
Classification	Other metal	Natural form	Solid	Thermal Cond: W/(cm K)	0.46
Configuration	[Xe]4f145d106s2p1	Crystal structure	Hex	Electrical Cond	0.0617
Oxidation states	1,3	Density	11.8	Abundance: mg/kg-crust	0.85
Electronegativity	1.8	Vaporization: kJ/Mole	162.1
Sir William Crookes discovered thallium in 1861.  Crookes presumed the element was sulfur-like,but in 1862, he and Claude-Auguste Lamy independently isolated thallium. They found it to be a metal unlike the elements in the group containing sulfur.			Uses - IR detectors, photocells, rat and ant poison