In the given graph,which point represents an alkali metal with the least atomic number (Period number $= 3$)?

Consider the following ionisation reactions:

$A_{(g)} \to A^{+}_{(g)} + e^-, \ A_1$	$B_{(g)} \to B^{+}_{(g)} + e^-, \ B_1$
$B^{+}_{(g)} \to B^{2+}_{(g)} + e^-, \ B_2$	$C_{(g)} \to C^{+}_{(g)} + e^-, \ C_1$
$C^{+}_{(g)} \to C^{2+}_{(g)} + e^-, \ C_2$	$C^{2+}_{(g)} \to C^{3+}_{(g)} + e^-, \ C_3$

If the monovalent positive ion of $A$,divalent positive ion of $B$,and trivalent positive ion of $C$ have zero electrons,then which of the following is the incorrect order of the corresponding $I.E.$?

Ionization enthalpy of an atom is equal to

Which of the following elements has the lowest $IE_1$ value?

For an element,the values of $IP_1, IP_2, IP_3, IP_4$ and $IP_5$ are $7.1, 14.3, 34.5, 46.8$ and $162.2 \ eV$ respectively. Which of the following is the most likely element?

The first ionisation potentials $(eV)$ of $Be$ and $B$ respectively are :-