• question_answer ) Which of the following species contains equal number of$\sigma -$and$\pi -$bonds? A) ${{(CN)}_{2}}$B) $C{{H}_{2}}{{(CN)}_{2}}$C)  $HCO_{3}^{-}$D) $Xe{{O}_{4}}$

$C{{H}_{2}}{{(CN)}_{2}}\,\,\,\,\,\,N\equiv C-\underset{H}{\overset{N}{\mathop{\underset{|}{\overset{|}{\mathop{C}}}\,}}}\,-C\equiv N(6\sigma +4\pi )$ ${{(CN)}_{2}}\,\,\,\,\,\,N\equiv C-C=N(3\sigma +4\pi )$