Thallium ( /ˈθæliəm/ THAL-ee-əm) je apilese kemika pelu ami-idamo Tl ati nomba atomu 81. Dong, Z.-C.; Corbett, J. D. (1996). "Na23K9Tl15.3: An Unusual Zintl Compound Containing Apparent Tl57−, Tl48−, Tl37−, and Tl5− Anions". Inorganic Chemistry 35 (11): 3107–12. doi:10.1021/ic960014z.  Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.