The first ionization enthalpies of four consecutive elements present in the second period of the periodic table are $8.3, 11.3, 14.5$ and $13.6 \ eV,$ respectively. Which one of the following is the first ionization enthalpy of nitrogen?

In the given graph,which point represents an alkali metal with the least atomic number (Period number $= 3$)?

In the second period of the modern periodic table,two elements $X$ and $Y$ have higher first ionization enthalpy values than the preceding and succeeding elements. $X$ and $Y$ are respectively

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A:$ The first ionisation enthalpy decreases across a period.
Reason $R:$ The increasing nuclear charge outweighs the shielding across the period.
In the light of the above statements,choose the most appropriate from the options given below:

Which of the following is not the correct increasing order of ionisation energy?

The correct order in which the first ionisation potential increases is