Among the following, the molecule expected to be stabilized by anion formation is: C2, O2, NO, F2

🧠 A molecule is stabilized by anion formation when adding one electron increases its bond order.

🗺️ Check bond order before and after adding e⁻:

| Molecule | e⁻ | BO | After anion | New BO | Change | |----------|----|----|-------------|--------|--------| | $\mathrm{C_2}$ | 12 | 2 | $\mathrm{C_2^-}$ (13e) | 2.5 | ↑ ✓ | | $\mathrm{O_2}$ | 16 | 2 | $\mathrm{O_2^-}$ (17e) | 1.5 | ↓ ✗ | | NO | 15 | 2.5 | $\mathrm{NO^-}$ (16e) | 2 | ↓ ✗ | | $\mathrm{F_2}$ | 18 | 1 | $\mathrm{F_2^-}$ (19e) | 0.5 | ↓ ✗ |

⚡ For $\mathrm{C_2}$ , the 13th electron enters a bonding $\sigma_{2p}$ orbital (since all π and σ below it are filled for N₂-type ordering), raising the bond order.

$\boxed{\text{Answer: } \mathrm{C_2}}$