Thallium (Tl) belongs to the Group 3 - Boron Family of elements. In the new IUPAC grouping, The Boron family is now Group 13.
Page updated 2/25/2016. Carrier, clerk, mail handlers, and distribution associates are required to take and pass the 473 Postal Exam. Other applicants including motor vehicle operators, mechanic, clerical, electronic technician, machinist, and trades must also pass a written test.
But if there is one thing that has remained the same from the moment of its founding, it is the job of a mail processing clerk. It is an entry-level job for which prospective candidates need to pass the postal battery exam 473-e. As far as the education requirement is concerned, a high school diploma will suffice.