Question

Which of the following halogens does always show oxidation state -1 ?

• A. Cl
• B. F
• C. Br
• D. I

Hint:

Fluorine is the "king" of electronegativity; it never shares its electrons in a way that gives it a positive charge.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
We need to identify the halogen that never exhibits any positive oxidation state in its compounds.
Step 2: Detailed Explanation:
1. Oxidation state depends on electronegativity and electronic configuration.
2. Fluorine ($F$) is the most electronegative element in the entire periodic table. Therefore, it always takes an electron from any other element (except in $F_2$ where it is 0).
3. Other halogens ($Cl, Br, I$) have vacant d-orbitals in their valence shell, which allows them to expand their octet and show positive oxidation states like $+1, +3, +5, +7$ when bonded to more electronegative elements (like $O$ or $F$).
4. Fluorine lacks d-orbitals and is too electronegative to ever have a positive oxidation state. It only shows $-1$ oxidation state in all its compounds.
Step 4: Final Answer:
Fluorine (F) always shows a $-1$ oxidation state.