What is meant by diagonal relationship?

Count the number of properties which have higher value for '$O$' atom than that of '$S$': Ionisation potential, Electron affinity, Covalent radius, Electronegativity.

Match List-$I$ with List-$II$.

List-$I$ (Elements)	List-$II$ (Properties)
$A. Cl, S$	$I. \text{Elements with highest electronegativity}$
$B. Ge, As$	$II. \text{Elements with largest atomic size}$
$C. Fr, Ra$	$III. \text{Elements which show properties of both metals and non-metals}$
$D. F, O$	$IV. \text{Elements with highest negative electron gain enthalpy}$

Choose the correct answer from the options given below:

Consider the following elements arranged in a periodic table segment as shown in the image.
Which of the following is/are true about $A^{\prime}, B^{\prime}, C^{\prime}$ and $D^{\prime}$?
$A$. Order of atomic radii: $B^{\prime} < A^{\prime} < D^{\prime} < C^{\prime}$
$B$. Order of metallic character: $B^{\prime} < A^{\prime} < D^{\prime} < C^{\prime}$
$C$. Size of the element: $D^{\prime} < C^{\prime} < B^{\prime} < A^{\prime}$
$D$. Order of ionic radii: $B^{\prime+} < A^{\prime+} < D^{\prime+} < C^{\prime+}$
Choose the correct answer from the options given below:

Which of these does not reflect the periodicity of the elements?

Which of the following sets is incorrect?