Identify the incorrect set$(s)$ among the following periodic trends:
$(a)$ Ionisation energy: $Na < Li < B < Be$
$(b)$ Electron gain enthalpy: $N < P < O < S$
$(c)$ Electronegativity: $S < O < Cl < F$
$(d)$ Atomic radii: $F < N < O < Na$

Which of the following orders is incorrect?

Given below are two statements:
Statement $I$ : The correct order of first ionization enthalpy values of $Li, Na, F$ and $Cl$ is $Na < Li < Cl < F$.
Statement $II$ : The correct order of negative electron gain enthalpy values of $Li, Na, F$ and $Cl$ is $Na < Li < F < Cl$.
In the light of the above statements,choose the correct answer from the options given below :

Maximum enthalpy change is associated with which of the following reactions?

Describe the periodicity of the first ionization enthalpy for elements with atomic numbers $1$ to $60$.

Which elements in groups $1$ to $17$ differ in many respects from the other elements of their respective groups?