Question

Find out the total number of diamagnetic species is :
$K _{2} O _{2}, NiNH _{36}{ }^{2+}, MnBr _{4}{ }^{2-}, NO _{2}$ $CuCl _{4}{ }^{3-}, Coox _{3}{ }^{3-}, BaO _{2}, KO _{2}, KCN$

Answer 1

A species is said to be diamagnetic when it has all the paired electrons. Similarly, if the species contain unpaired electrons is is said to be paramagnetic.
$K_{2}O_{2},\left[CuCl_{4}\right]^{3 -},BaO_{2},KO_{2}$ and $KCN$ are diamagnetic species. Rest all are paramagnetic.