The first ionization potential values (in $eV$) for nitrogen and oxygen atoms are respectively:

Among the second period elements,the actual ionization enthalpies are in the order $Li < B < Be < C < O < N < F < Ne$. Explain why:
$(i)$ $Be$ has higher $\Delta_{i}H$ than $B$
$(ii)$ $O$ has lower $\Delta_{i}H$ than $N$ and $F$?

Observe the following statements.
Statement $(A)$: In general,the ionisation potential value decreases on moving down in the group.
Statement $(B)$: The $1$st ionisation potential of sodium is greater than that of potassium.
Correct answer is:

In the photoelectric effect,if the work functions of $Li$,$Na$,and $Rb$ are $2.41 \ eV$,$2.30 \ eV$,and $2.09 \ eV$ respectively,the work function of $K$ could approximately be in $eV$?

Among $Be$, $B$, $Mg$ and $Al$, the second ionisation potential is maximum for

Which of the following represents the correct decreasing order of the first ionization energy for $Ba$,$Sr$,$Ca$,and $Mg$?