there are some species given below
(i) O⁺₂
(ii) CO
(iii) B₂
(iv) O⁻₂
(v) NO⁺
(vi) He⁺₂
(vii) C²⁺₂
(vii) CN⁻
(xi) N⁻₂
Total number of species which have their fractional bond order