Electronic Configuration, Oxidation States — Prelims Questions

Which of the following statements about the oxidation states of halogens is INCORRECT?

What is the oxidation state of Iodine in $H_5IO_6$ (periodic acid)?

Which of the following electronic configurations represents a halogen in its ground state?

In which of the following compounds does Chlorine exhibit its highest possible oxidation state?

Which of the following statements correctly explains why Fluorine does not exhibit positive oxidation states?

Which of the following interhalogen compounds involves a halogen in the +5 oxidation state?