Apply molecular orbital theory to predict which species has the strongest bond. apply molecular orbital theory to predict which species has the strongest bond. o+2 o−2 o2 all bonds are equivalent according to molecular orbital theory.

Explanation:

We must fill in the MO diagrams and calculate the bond orders for each species.  

1. O₂⁺

An O atom has six valence electrons, so two O atoms have 12 valence electrons.

O₂⁺ has lost an electron. In Figure 1, we give one O atom six electrons and the other atom five.

Then we add 11 electrons to the molecular orbitals, using the same rules as for atomic orbitals.

Bond order = (Bonding electrons – antibonding electrons)/2

BO = ½(B – A)

B = ½ (8 – 3) = 2.5

2. O₂

O₂ has 12 valence electrons, so we put 12 electrons in Figure 2 and calculate the bonding order.

B = ½ (8 - 4) = 2

3. O₂⁻

O₂⁻ has 13 valence electrons, so we put 13 electrons in Figure 3 and calculate the bonding order.

B = ½ (8 – 5) = 1.5

The species with the highest bond order has the strongest bonds.

O₂⁺ has the highest bond order, so has the strongest bonds.