How would you figure this out?

The elegant organization of the periodic table allows for bonding properties to be determined based on the location of an element in the table. Answer the questions in Parts 1-3 based on the colored positions on the periodic table below: Oxygen will always form an ionic compound in a 2:1 ratio with the element. Part 3 (1 point) Which two elements can have different charges depending on the compound they are found in? Choose one or more: red green orange blue purple