According to molecular orbital theory which of the following lists rank the nitrogen species in terms of increasing bond order?

Q. According to molecular orbital theory which of the following lists rank the nitrogen species in terms of increasing bond order?

1. N−2 < N2 < N2−2
2. N2−2 < N−2 < N2
3. N2 < N2−2 < N−2
4. N−2 < N2−2 < N2

Answer: N2−2 < N−2 < N2