The number of unpaired electrons responsible for the paramagnetic nature of each complex species is calculated as follows:

Complex:
Ion:

Electronic Configuration:

Orbital Population:

Unpaired Electrons: 1
Complex:
Ion:

Electronic Configuration:
Orbital Population:

Unpaired Electrons: 5
Complex:
Ion:

Electronic Configuration:

Orbital Population:

Unpaired Electrons: 4
Complex:
Ion:

Electronic Configuration:

Orbital Population:

Unpaired Electrons: 2

Each complex's paramagnetic nature is due to the specific number of unpaired electrons as indicated above.