If the electronic configuration of $A^{-}$ is $[Ar] \ 4s^2 \ 3d^{10} \ 4p^1$,then $A^{+2}$ will belong to which group and period?

The cause of the diagonal relationship is:

In which of the following sets,elements are not correctly arranged with the property shown in brackets?

The element with a very high ionization enthalpy but zero electron gain enthalpy is ....

Consider the following values of $IE$ $(eV)$ for elements $W$ and $X$:

Element	$IE_1$	$IE_2$	$IE_3$	$IE_4$
$W$	$10.5$	$15.5$	$24.9$	$79.8$
$X$	$8$	$14.8$	$78.9$	$105.8$

Other two elements $Y$ and $Z$ have outer electronic configuration $ns^2 np^4$ and $ns^2 np^5$ respectively. According to the given information,which of the following compound$(s)$ is/are not possible?
$(a) W_2Y_3, (b) X_2Y_3, (c) WZ_2, (d) XZ_2$

In which of the following arrangements,the sequence does not strictly follow the property indicated against it?