Paramagnetic Species with Bond Order Equal to One
The number of species from the following which are paramagnetic
and with bond order equal to one is ________.
H2, He2+, O2+,
N22−, O22−, F2,
Ne2+, B2
Explanation
A species must satisfy both conditions:
- It must be paramagnetic (at least one unpaired electron).
- Its bond order must be exactly equal to one.
- H₂ → Bond order = 1 but diamagnetic ✘
- He₂⁺ → Bond order = 0.5 ✘
- O₂⁺ → Bond order = 2.5 ✘
- N₂²⁻ → Bond order = 2 ✘
- O₂²⁻ → Bond order = 1 but diamagnetic ✘
- F₂ → Bond order = 1 but diamagnetic ✘
- Ne₂⁺ → Bond order = 0.5 ✘
- B₂ → Bond order = 1 and paramagnetic ✔
Hence, only one species (B₂) satisfies both conditions.