For the first row trasition metals the `E^(ɵ)` value are:
`{:(underset(-1.18)(V),,underset(-0.91)(Cr),,underset(-1.18)(Mn),,underset(-0.44)(Fe),,underset(-0.28)(Co),,underset(-0.25)(Ni),underset(+0.34)(Cu)):}`
Explain the irregularity in the abpve values.