For the second period elements the correct increasing order of first ionization enthalpy is:

For the second period elements the correct increasing order of first ionization enthalpy is:
  1. Li<Be<B<C<N<O<F<Ne.
  2. Li<B<Be<C<O<N<F<Ne.
  3. Li<B<Be<C<N<O<F<Ne.
  4. Li<Be<B<C<O<N<F<Ne.

Solution

Ionisation Enthalpy ∝ Zeffective ∝ Stable configuration.

As we move from Left to right in a period, ZEffective  increases. So, ionization enthalpy increases. The exceptions are as give below:

Asked in: NEET 2019 (All India)

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