Answer: Iodine, I
Explanation: Oxygen family is the group that has Oxygen at the top of the column, group 16, meaning it has 16 valence electrons. On some periodic tables, there will be a 6A at the top instead. After finding the group, go to the left edge of the periodic table and find 5. Then go right in the 5 row, which is period 5, and stop when you reach the oxygen family. If done correctly, you will end on Iodine.