The pair of species with the same bond order is :

Options

A. `O_2^(2-), B_2`
B. `O_2^(+), NO^(+)`
C. `NO, CO`
D. `N_2, O_2`

Answer

A

Explanation

According to molcular orbital theory.
`O_2^(2-)` (8+8+2=18)
`=sigma1s^2, overset***sigma1s^2,sigma2s^2, overset***sigma2s^2,sigma2s_z^2, pi2p_x^2~~pi2p_y^2 , overset***pi2p_x^2~~overset***pi2p_y^2`
Bond order (BC)=`(N_b-N_a)/2 =(10-8)/2=1`
`B_2`(5+5=10)=`sigma1s^2, overset***sigma1s^2, sigma2s^2, overset***sigma2s^2,pi2p_x^1~~pi2p_y^1`
BO=`(6-4)/2=1`
Thus, `O_2^(2-)` and `B_2` have the same bond order .
NOTE
BO of `O_2^+=2.5, NO^+ =3, NO=2.5, CO=3, N_2=3 and O_2=2`