As per molecular orbital theory, bond order of `Li_(2)` is x and that of `Li_(2)^(-)` is y . The value of (x - y) is:

Answer

0.5

Explanation

`Li_(2) rArr sigma1s^(2)sigma^(8)1s^(2) 2s^(2)`
Bond order `=(N_(b) - N_(a))/2`
`=(4-2)/2 = 1`
`therefore x = 1`
`Li_(2)^(-) rArr sigma1s^(2)sigma^(*)1s^(2) sigma2s^(2) sigma^(*)2s^(1)`
Bond order `= (4-3)/2 = 1/2 = 0.5`
`therefore y = 0.5`
`therefore (x-y) = (1-0.5)= 0.5`