Which specie has unpaired electrons in antibonding molecular orbitals_______________?
Correct answer: B. N2-2
- A. O2+2
- B. N2-2
- C. B2
- D. O2-2
Explanation
N2 has 10 valence electrons, and N2^2- has 12, so the two additional electrons enter antibonding pi* orbitals separately according to Hund's rule, giving unpaired electrons. O2^2+ and O2^2- have paired antibonding electrons, while B2 has unpaired electrons in bonding pi orbitals. The likely mistake is choosing B2 because it has unpaired electrons without checking whether those electrons are in bonding or antibonding orbitals.
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