What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of their atoms : `3d^(3),3d^(5),3d^(8)`and `3d^(4)`?

Answer

Stable oxidation state:
Vanadium =`3d^(3):(+2),+3,+4 and +5`
Chromium=`3d^(5):+2,+3,+6`
Manganese=`3d^(5):+2,+4,+6,+7`
Nickel=`3d^(5):+2,+3,+4("in complex")`
In ground state for `3d^(4)` configuration no one metal occur.