What is the basic difference between the terms electron gain enthalpy and electronegativity?

Assign true $(T)$ and false $(F)$ for the following statements and select the correct option for your answer:
$(a) \, IP$ of $O_{(g)}$ is less than $IP$ of $O_{(g)}^{-}$
$(b) \, IP$ of $Ne_{(g)}$ is greater than $IP$ of $Ne_{(g)}^{+}$
$(c) \, EA$ of $O_{(g)}^{+}$ is greater than $EA$ of $O_{(g)}$
$(d) \, IP$ of $N_{(g)}$ is greater than $IP$ of $N_{(g)}^{+}$

Which pair of elements exhibits a diagonal relationship in the periodic table?

Diagonal relationship is shown by

Consider the following elements arranged in a periodic table segment as shown in the image (Row $1$: $A^{\prime}, B^{\prime}$; Row $2$: $C^{\prime}, D^{\prime}$ where $A^{\prime}$ is above $C^{\prime}$ and $B^{\prime}$ is above $D^{\prime}$). 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:

Consider the following statements:
$(I)$ Ionic mobility of hydrated $Li^+$ is greater than that of hydrated $Na^+$.
$(II)$ $IE_1$ of $P$ atom is higher than that of $S$ atom,while $IE_2$ of $S$ atom is higher than that of $P$ atom.
$(III)$ Lithium is a strong reducing agent in aqueous medium.
Which of the above statements is/are correct?