• # question_answer Among $[Ni{{(CO)}_{4}}],{{[NiC{{l}_{4}}]}^{2-}},[Co{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]Cl,$ $N{{a}_{3}}[Co{{F}_{6}}],N{{a}_{2}}{{O}_{2}}$ and $Cs{{O}_{2}}$ the total number of paramagnetic compounds is A) 2 B) 3 C) 4 D) 5

 Compound/ Ion of compound Magnetic nature 1. $[Ni{{(CO)}_{4}}]$ Diamagnetic 2. ${{[NiC{{l}_{4}}]}^{2-}}$ Paramagnetic 3. $a[Co{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]Cl~$ Diamagnetic 4. $Na[Co{{F}_{6}}]$ Paramagnetic 5. $N{{a}_{2}}{{O}_{2}}$ Diamagnetic 6. $Cs{{O}_{2}}$ Paramagnetic