Answer
See the explanation
Work Step by Step
1. Using the molecular orbital model, let's write the electron configurations and calculate the bond orders for the given diatomic species:
a. CO (Carbon Monoxide):
Electron configuration: (1s)^2 (2s)^2 (2p)^4 - (1s)^2 (2s)^2 (2p)^2
Bond order = (8 - 2) / 2 = 3
The CO molecule is diamagnetic.
b. $CO^{+}$ (Carbonyl Cation):
Electron configuration: (1s)^2 (2s)^2 (2p)^3 - (1s)^2 (2s)^2 (2p)^2
Bond order = (7 - 2) / 2 = 2.5
The $CO^{+}$ cation is paramagnetic.
c. $CO^{2+}$ (Dicarbonyl Dication):
Electron configuration: (1s)^2 (2s)^2 (2p)^2 - (1s)^2 (2s)^2 (2p)^2
Bond order = (6 - 2) / 2 = 2
The $CO^{2+}$ cation is diamagnetic.
Ordering the species in increasing bond length and bond energy:
$CO^{2+}$ < $CO^{+}$ < CO
The bond length and bond energy follow the trend:
$CO
