• # question_answer The oxide which forms dimer is A) ${{N}_{2}}{{O}_{3}}$                 B) ${{N}_{2}}{{O}_{5}}$     C)      $N{{O}_{2}}$                     D)      ${{N}_{2}}O$

$N{{O}_{2}}$can form dimer, ${{N}_{2}}{{O}_{4}},$due to the presence of unpaired electrons on nitrogen atom. Hence, the correct option is (c).