Final answer:
The chemical symbol for thallium is Tl. It is a post-transition metal with the atomic number 81 and should not be confused with titanium, which has the symbol Ti.
Step-by-step explanation:
The chemical symbol for thallium is Tl. This abbreviation represents thallium on the periodic table of elements and is used universally in chemical equations and formulae. For instance, the compound thallium iodide is denoted as TlI, indicating a 1:1 ratio of thallium to iodide ions in its structure.
Thallium is a post-transition metal with the atomic number 81, as seen in the periodic table, and it is distinct from other elements such as titanium (Ti), whose chemical symbol might seem similar at a glance. It is important to be familiar with chemical symbols to effectively communicate and understand chemical compositions in the study of chemistry.