## Chemistry: Molecular Approach (4th Edition)

Unlike main-group metals that tend to exhibit only one oxidation state, the transition metals often exhibit a variety of oxidation states since they can lose the d electrons without high energy penalty. This can be explained by taking manganese as an example: the highest oxidation state of manganese is $+7$, which corresponds to loss of all the electrons in the $4s$ and $3d$ orbitals, leaving the noble gas electron configuration. It also exhibits $M{{n}^{2+}}$ by the loss of two electrons present in the $~4s$ orbital.