Question

Fluorine shows only -1 oxidation state while other halogens show -1, +1, +3, +5 and +7 oxidation states. Explain.

Answer 1

• Halogens have outer electronic configuration ns²np⁵ 
• Halogens have tendency to gain or share one electron to attain the stable configuration of nearest inert element with configuration ns²np⁵.
• Hence they are monovalent and show oxidation state – 1.
• Since fluorine does not have vacant dorbital, it shows only one oxidation state of – 1 while all other halogens show variable oxidation states from – 1 to + 7.
• These oxidation states are, – 1, + 1, + 3, + 5 and + 7. Cl and Br also show oxidation states + 4 and + 6 in their oxides and oxyaClds.