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Questions
Give reasons:
Transition metals show variable oxidation states.
Account for the following:
Transition metals show variable oxidation states.
Explain giving reasons:
Transition elements exhibit variable oxidation states.
Why do transition elements exhibit variable oxidation states?
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Solution 1
- The variable oxidation states of transition elements are due to the participation of ns and (n − 1) d-electrons in bonding.
- A lower oxidation state is exhibited when the ns-electrons take part in bonding.
- Higher oxidation states are exhibited when the (n − 1) d-electrons take part in bonding.
- Since there is very little energy difference between these orbitals, both energy levels can be used for bond formation.
Thus, transition elements exhibit variable oxidation states.
Solution 2
- In transition elements, the 3d and 4s electrons are close in energy and can be lost in different numbers during reactions.
- The involvement of both (n − 1) d and ns electrons in bonding allows multiple oxidation states.
- Stability of oxidation states is influenced by half-filled or fully filled d-subshells, leading to preferred oxidation numbers.
- For example, manganese shows oxidation states from +2 to +7, reflecting this variability.
Hence, transition elements show a wide range of oxidation states because they can lose different numbers of d and s electrons easily.
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