The valence shell electronic configuration of $Cr^{2+}$ ion is

Explain giving reasons:
$(i)$ Transition metals and many of their compounds show paramagnetic behaviour.
$(ii)$ The enthalpies of atomisation of the transition metals are high.
$(iii)$ The transition metals generally form coloured compounds.
$(iv)$ Transition metals and their many compounds act as good catalysts.

Among the following series of transition metal ions,the one in which all the metal ions have $3d^2$ electronic configuration (excluding the $3p^6$ core) is (Atomic number: $Ti=22, V=23, Cr=24, Mn=25$)

The general electronic configuration of transition elements is

Consider $n$ as the number of lone pairs of electrons present in the equatorial position of the most stable structure of $ClF_3$. The ions from the following with $n$ number of unpaired electrons are :
$A. V^{3+}$
$B. Ti^{3+}$
$C. Cu^{2+}$
$D. Ni^{2+}$
$E. Ti^{2+}$
Choose the correct answer from the options given below :

The set of elements which obey the general electronic configuration $(n-1)d^{1-10}ns^2$ is