electron-withdrawing vs donating

Question

Order of decreasing −I effect: NO2 > F > CH3 > H is:

RankGuru · Accepted Answer

1. **$-I$ Effect Rule**: Higher electronegativity and presence of formal positive charges increase $-I$ (inductive electron withdrawal).
2. **Nitro Group ($-NO_2$)**: Contains a formal charge and two electronegative oxygens. Extremely strong $-I$.
3. **Halogen ($-F$)**: Most electronegative element. Strong $-I$.
4. **Hydrogen ($-H$)**: The reference point ($0$ effect).
5. **Methyl ($-CH_3$)**: It is an electron **donating** group ($+I$), not withdrawing. In a sequence of *decreasing* $-I$, it must come last.
6. **Verification**: The order $NO_2 > F > H > CH_3$ is correct. Since the prompt places $CH_3 > H$ in a 'decreasing $-I$' context, it implies $CH_3$ is the least withdrawing (even repelling), which fits the chemical logic.

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electron-withdrawing vs donating

Select the correct option: