Q43 / 180 · NEET 2019 (All India) · Chemistry

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

  • A
    Li<Be<B<C<N<O<F<Ne.
  • Correct answer
    B
    Li<B<Be<C<O<N<F<Ne.
  • C
    Li<B<Be<C<N<O<F<Ne.
  • D
    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:

Figure

Hence, the correct answer is option: 'B'.

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