question_answer 63)

  Which of the following statements is not correct from theview point of molecular theory? (a) \[B{{e}_{2}}\]is not a stable molecule              (b) \[H{{e}_{2}}\]is not stable but \[He_{2}^{+}\] is expected to exist (c) Bond strength of \[{{N}_{2}}\] is maximum among homonuclear diatomic molecules belonging to second period (d) The order of energies of molecular orbitals in \[{{N}_{2}}\]molecule is \[\sigma 2s<{{\sigma }^{*}}2s<\sigma 2{{p}_{z}}<(\pi 2{{p}_{x}}=\pi 2{{p}_{y}})<\]\[({{\pi }^{*}}2{{p}_{x}}={{\pi }^{*}}2{{p}_{y}})<{{\sigma }^{*}}2{{p}_{z}}\]

Answer:

  (d) The order of energies of molecular orbitals in \[{{N}_{2}}\]molecule is : \[\sigma 2s<{{\sigma }^{*}}2s(\pi 2{{p}_{x}}=\pi 2{{p}_{y}})<\sigma 2{{p}_{z}}<({{\pi }^{*}}2{{p}_{x}}={{\pi }^{*}}2{{p}_{y}})\]           \[<{{\sigma }^{*}}2{{p}_{z}}\]