Which one of the following is paramagnetic?

Which one of the following has a magnetic moment of $1.75 \ BM$?

How would you account for the irregular variation of ionization enthalpies (first and second) in the first series of the transition elements?

Match List-$I$ with List-$II$:

List-$I$ ($\text{Transition metal ion}$)	List-$II$ ($\text{Spin only magnetic moment (B.M.)}$)
$A$. $Ti^{3+}$	$I$. $3.87$
$B$. $V^{2+}$	$II$. $0.00$
$C$. $Ni^{2+}$	$III$. $1.73$
$D$. $Sc^{3+}$	$IV$. $2.84$

Choose the correct answer from the options given below:

The transition element that has the lowest enthalpy of atomisation is

Assertion : $Cr(VI)$ in the form of dichromate in acidic medium is a strong oxidising agent whereas $MoO_3$ and $WO_3$ are not.
Reason : $Mo(VI)$ and $W(VI)$ are found to be more stable than $Cr(VI)$.