Question

Which region(s) of the periodic table contains elements that can adopt both positive and negative oxidation numbers?

Answer 1

The region(s) of the periodic table which contains elements that can adopt both positive and negative oxidation numbers would be the nonmetal region. As you look at the periodic table, you can see that some elements on the right side of the table would have two oxidation states written one positive and other a negative sign. 

Answer 2

Answer : The halogen group of non metals and metalloids these regions will exhibit the trend of having positive and negative oxidation numbers. They are placed on right side of the modern periodic table. The trend of having two oxidation states where one is positive and other is negative in the Groups 13 to 16 of the modern periodic table which contains one or more metalloids, in addition to metals, nonmetals, or both.