Which among the following is $NOT$ a feature of $S_N2$ mechanism?

Which of the following is not a part of the stamen?

The number of divisors of $n = 38808$ (excluding $1$ and $n$) is

From the following thermochemical equations,find out the heat of ionisation $Z$ for a weak acid $HA$:
$HA \to A^{-} + H^{+}$,$\Delta H = Z$
$H^{+} + OH^{-} \to H_2O$,$\Delta H = X$
$HA + OH^{-} \to A^{-} + H_2O$,$\Delta H = Y$

In an electrochemicalcell, dichromate ions in aqueous acidic medium are reduced to $Cr ^{3+}$. The current $($in amperes$)$ that flows through the cell for $48.25$ minutes to produce $1$ mole of $Cr ^{3+}$ is $....$ . Use: $1$ Faraday $=96500 C mol ^{-1}$

$A$ body of mass $2 \, kg$ slides down a curved track which is a quadrant of a circle of radius $1 \, m$. All the surfaces are frictionless. If the body starts from rest,its speed at the bottom of the track is ................. $m/s$.