The ionisation energy of nitrogen is more than that of oxygen because :-

Ionization energy is highest for

Discuss the trend of the first ionisation enthalpy in the same period and explain why it occurs.

The first four ionization energy values of an element are $191$,$578$,$872$ and $5962 \ kcal$. The number of valence electrons in the element is

The successive ionisation energies (starting from the $1^{st}$) of an element are $801$,$2430$,$3660$,$25000$,and $32800 \ kJ \ mol^{-1}$,respectively. The element is:

Assertion $(A)$: Boron has a smaller first ionisation enthalpy than beryllium.
Reason $(R)$: The penetration of a $2s$-electron to the nucleus is more than the $2p$-electron; hence,the $2p$-electron is more shielded by the inner core of electrons than $2s$-electrons.