# Which of the following are diamagnetics ? $(i)\;C_2 \\ (ii)\;He_2 \\(iii)\;Li_2 \\(iv)\;N_2$

$(a)\;\text{(i),(ii) and (iii) } \\ (b)\;\text{(i),(ii) and (iv)} \\(c)\;\text{(i),(iii) and (iv) } \\(d)\;\text{(ii),(iii) and (iv)}$

$C_2,He_2$ and $Li_2$ have bond order equal to zero.
The number of unpaired electrons they posses is also zero.
Hence they are diamagnetic.
Hence a is the correct answer.