Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
Manganese exhibits the largest number of oxidation states in the 3d series. It displays all oxidation states from +2 to +7.
This occurs because elements that give the greatest number of oxidation states are found in or near the middle of the series. At the extreme ends of the series, the number of oxidation states is limited; early elements have too few electrons to lose or share, while later elements have too many d electrons (and fewer orbitals available in which to share electrons) for higher valence.
Explanation
The textbook context explicitly states that Manganese exhibits all oxidation states from +2 to +7. It explains that the elements in or near the middle of the series exhibit the greatest number of oxidation states. The reason provided is that elements at the ends have either too few electrons to lose/share or too many d electrons resulting in fewer available orbitals for sharing, whereas elements in the middle have a balance that allows for variable oxidation states.
Solution Steps
Identify the element: The text states that elements in or near the middle of the series give the greatest number of oxidation states, specifically naming Manganese.
State the range: Manganese exhibits all oxidation states from +2 to +7.
Explain the reason: The middle of the series allows for an optimal number of electrons to lose or share, unlike the extreme ends which are limited by too few or too many d electrons.