Question

Why transition elements show a variable oxidation state?

Answer 1

Answer:

They show variable oxidation state because transition metals have (n-1)d orbitals empty that are closer to the outermost ns orbital in energy levels. ... The energy difference between these ns and (n-1)d orbitals is less. Thus, both can share electrons during bond formation and therefore, both contribute towards bonding.

Explanation:

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Answer 2

Answer:

They show variable oxidation state because transition metals have (n-1)d orbitals empty that are closer to the outermost ns orbital in energy levels. ... The energy difference between these ns and (n-1)d orbitals is less. Thus, both can share electrons during bond formation and therefore, both contribute towards bonding.