Question
Explain the deviation in ionisation enthalpy of some elements from the general trend by using.
✓
Answer
Ionisation enthalpy increases in a period with increase in atomic number. The graph shows few exceptions and not the linear relationship. Ionisation enthalpy of Be is greater than that of B due to filled s-orbital in Be $\left(\mathrm{Be}-\mathrm{I} . \mathrm{s}^2 1 \mathrm{~s}^2, \mathrm{~B}-1 \mathrm{~s}^2 2 \mathrm{~s}^2 2 \mathrm{p}^1\right)$
Ionisation enthalpy of N is greater than that of O due to half-filled p-orbitals in nitrogen. $\left(N-1 s^2 2 s^2 2 p^3, O-1 s^2 2 s^2 2 p^4\right)$.
Ionisation enthalpy of N is greater than that of O due to half-filled p-orbitals in nitrogen. $\left(N-1 s^2 2 s^2 2 p^3, O-1 s^2 2 s^2 2 p^4\right)$.
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