Which of the following statements is incorrect?

$X$,$Y$,and $Z$ are elements of the same period and belong to the $p$-block. $Y$ has a positive value of $\Delta_{eg}H$ (electron gain enthalpy),and $Z$ has the highest $2^{nd}$ ionization energy $(I.E.)$ among them. What is the correct order of their atomic numbers?
$(a)$ $X < Y < Z$
$(b)$ $X < Z < Y$
$(c)$ $Y < Z < X$
$(d)$ $Z < Y < X$

Which of the following orders is correct?

Which of the following statements is not correct regarding the classification of elements in the periodic table?

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

Which of the following statements are correct for the classification of elements?
$I$. The properties of elements are periodic functions of their atomic numbers.
$II$. Non-metallic elements are less in number than the metallic elements.
$III$. The first ionisation energies of elements along a period do not vary in a regular manner.
$IV$. The ground state electronic configuration of $Pd (Z=46)$ is $[Kr] 4d^8 5s^2$.