Why do the transition elements exhibits variable oxidation states?
In transition elements, the $d$-orbitals are incompletely occupied in such a way that there oxidation state differs by unity.
The general electronic configuration of transition elements is $(n-1) d^{1-10} n s^{1-2}$. Due to very less difference in the energies of ( $n-1$ ) $d$-orbitals and $n s$-orbitals, the transition elements exhibit more than one oxidation states as electrons of both these shells can participate in chemical bonding. The $4 s$-electrons are responsible for lower oxidation state while both $3 d$ and $4 s$ electrons are responsible for higher oxidation states in first transition series.
Select the diamagnetic coloured compound:-
A blue colouration is not obtained when
Which of the following ions gives coloured solution
The oxoanion in which the oxidation state of the central atom is same as its group number in the periodic table is
Which one of the following ions is the most stable in aqueous solution?
(At. No. $Ti = 22, V = 23, Cr = 24, Mn = 25$)