The bond orders of `He _(2) ^(+)and He _(2)` are respectively

Options

A. `1/2, 0`
B. `0, 1/2`
C. `0,1`
D. `1,0`

Answer

A

Explanation

`He _(2)` molecular orbital has electronic configuration as `sigma 1s ^(2), aigma ***1s ^(2).`
Bond order = (electrons in bonding molecular orbital)-
`(("electrons in antibonding molecular orbital"))/(2)`
For `He _(2)`molecule bond order `= (2-2)/(2) =0`
Bond order is zero so, `He_(2)` molecule does not exist. In case of `He _(2) ^(+)` electronic configuration of molecular orbital is `sigma 1s^(2) sigma ^(***) 1s ^(1).`
Bond order `= (2-1)/(2) =1/2`