The hardness of $Cr$ is due to $......$ and metallic lustre is due to $.......$

Given below are two statements $:$
Statement $I : CrO_3$ is a stronger oxidizing agent than $MoO_3$
Statement $II : Cr(VI)$ is more stable than $Mo(VI)$
In the light of the above statements,choose the correct answer from the options given below.

Which one of the following ions has the same number of unpaired electrons as those present in $V^{3+}$ ion?

$3d-$ metal ions exhibit paramagnetic behavior because . . . . .

Which of the following represents the correct order of density for the given $3d$ series elements?

The $3d-$ elements show variable oxidation states. What is the maximum oxidation state shown by the element $Mn$?