Match of following.

List I (Element)	List II (Electron gain enthalpy (in $\mathrm{kJ} \mathrm{mol}^{-1}$ )
A F	I -141
B Cl	II -328
C O	III -200
D S	IV -349

The correct answer is

The bond lengths of diatomic molecules of elements $X$, $Y$ and $Z$ respectively are 143, 110 and 121 pm . The atomic numbers of $X, Y$, and $Z$ respectively are

The correct formula used to determine the formal charge (Q) on an atom in the given Lewis structure of a molecule or ion is ( $V=$ number of valence electrons in free atom, $U=$ number of unshared electrons on the atom, $B=$ number of bonds around the atom)

RMS velocity of one mole of an ideal gas was measen at different temperatures. A graph of $\left(\mu_{\mathrm{ma}}\right)^{-2}$ (on $Y$-sdi) and $T(\mathrm{~K})$ ( on $X$-axis) gave straight line passing through the origin and its slope is $249 \mathrm{~m}^2 \mathrm{~s}^{-2} \mathrm{~K}^{-1}$. What is the molar mass ( in kg mol${ }^{-1}$ ) of ideal gas? $ \left(R=83 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right) $