Stability of the species `Li_(2), Li_(2)^(-)` and `Li_(2)^(+)` increases in the order of

Options

A. `Li_(2)^(-) lt Li_(2) lt Li_(2)^(+)`
B. `Li_(2) lt Li_(2)^(+) lt Li_(2)^(-)`
C. `Li_(2)^(-) lt Li_(2)^(+) lt Li_(2)`
D. `Li_(2) lt Li_(2) lt Li_(2)^(+)`

Answer

C

Explanation

The bond order of the species is :
`Li_(2) (1), Li_(2)^(-) (0.5),Li_(2)^(+) (0.5)`
Higher the bond order greater is the stability Both `Li_(2) and Li_(2)^(+)` have B.O.= 0.5 But `Li_(2)^(-)` ion is less stable since it has an electron in the antibonding M.O. Therefore the correct order of stability is :
`Li_(2) lt Li_(2)^(+) ltLi_(2)`