Assertion : The [Ni( en )_3] Cl_2 (en = ethylene diamine) has lower...

$\left[\mathrm{Ni}(\mathrm{en})_3\right] \mathrm{Cl}_2$ is a chelating compound and chelated complexes are more stable than similar complexes with unidentate ligands as dissociation of the complex involves breaking of two bonds rather than one. In $\left[\mathrm{Ni}(\mathrm{en})_3\right] \mathrm{Cl}_2, \mathrm{Ni}$ with $d^8$ configuration shows octahedral geometry. Six electrons will occupy the $t_{2 g}$ orbitals and two electrons will occupy the $e_g$ orbitals.