• M (Bulk) $\rarr$ $M^o$ $\rarr$ $M^{n+}$ $\quad$ n=? aqueous

Important points

• Due to an increase in nuclear charge which go with the filling of the inner $d$ orbitals, there is an increase in ionization enthalpy along each series of the transition elements from left to right
• The successive enthalpies of these elements do not increase as abruptly as in the main group elements
• Within a triad, the first ionization energy is generally higher for the third than for the first and second metals, but the reverse is often true for removal of subsequent electrons

• The elements which give the greatest number of oxidation states occur in or near the middle of the series
• Mo(VI) and W(VI) are found to be more stable than Cr(VI)