Arrange the elements in ascending order of their oxidizing properties: Te, S, Se, F, O.

In this case, of course, it is simply necessary to use the “Periodic Table of Chemical Elements” by DI Mendeleev. And you can use the tables of changes in the electronegativity of atoms. But in principle, one periodic table is enough. And then just consider the arrangement of these chemical elements in the table. So, taking into account the atomic radii and electronegativity, the elements given in the condition of the problem can be arranged as follows in the order of increasing their oxidizing properties.

Te (tellurium), Se (selenium), S (sulfur), O (oxygen), F (fluorine).