Why 3d5 is more stable than 3d9 ?

Question

Why 3d5 is more stable than 3d9 ?

Answer 1

the d orbital can have a max of 10 electrons.

d5 is half filled, so as compared to d9 energy is more evenly distributed....

hence stability of d5 is greater than that of d9...

Answer 2

3d5 is more stable than 3d9 because as d orbital can accommodate maximum 10 electrons , and 3d5 is half filled ,therefore energy distribution is uniform in case of 3d5.

as each shell got one electron ,with same spin.

you should remember half filled orbit is more stable than partially filled.

Answer 3

there is one more reason i.e.

exchange factor

this is main reason behindv stability of half filled and full filled orbitals

look for it in a book

this is an imp. factor

Answer 4

There are 5 3d orbitals, and each can accommodate two electrons. Electrons, being negatively charged, repel each other. If two electrons move in the same region of space (in this case, in the same 3d orbital), then they will repel each other more strongly than if they move in different regions of space (i.e., in different 3d orbitals).

Thus, in 3d5 structure electron repulsions are less than in 3d9 structure, as all electrons in a 3d5 structure will occupy a different orbital, following Hund's Rule.

Therefore, 3d5 structure is energetically more stable than 3d9 structure.