Question

why do d block elements have variable valency​

Answer 1

Answer:

the ability of the transition metals to exhibit variable valency is generally attributed to the ability of more electrons in the in (n-1) D orbitals which are closer to the outermost and orbital in energy levels

mark me as brainliest

Answer 2

d-block elements have variable valency because there is not much difference in the energies of 4s and 3d orbitals.​

Explanation:

It is known that d-block elements are also called transition metals. General electronic configuration of d-block elements is $ns^{(1-2)}(n-1)d^{(1-10)}$.

As the valence electrons of d-block elements mostly reside in 4s or 3d-orbitals and there is not much difference in the energies of both 4s and 3d orbitals. As a result, it becomes easier of d-block elements to lose electrons from both these shells due to which they tend to show variable oxidation state.

Learn more about variable valency:

https://brainly.in/question/12038188

https://brainly.in/question/3061610

#Learnwithbrainly