Which of the following species exhibits the diamagnetic behaviour ?

Correct decreasing order of bond order of oxygen species in $I$ to $IV$

$(I)$   $Na_2O_2$

$(II)$  $O_2 [AsF_6]$

$(III)$  $CsO_2$

$(IV)$  $O_2$

Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them

Number of paramagnetic oxides among the following given oxides is ..... .

$\mathrm{Li}_{2} \mathrm{O}, \mathrm{CaO}, \mathrm{Na}_{2} \mathrm{O}_{2}, \mathrm{KO}_{2}, \mathrm{MgO}$ and $\mathrm{K}_{2} \mathrm{O}$

The maximum number of hydrogen bonds formed by a water molecule in ice is

Select incorrect statement