Number of lone pair (s) of electrons on central atom and the shape of $BrF _{3}$ molecule respectively, are ..... .
$0 ,$ triangular planar
$1,$ pyramidal.
$2,$ bent $T-$shape.
$1,$ bent $T-$shape
Which of the following species is paramagnetic?
Among the following species, the diamagnetic molecule is
The bond order of a molecule is given by
Compare the relative stability of the following species and indicate their magnetic properties;
$O _{2}, O _{2}^{+}, O _{2}^{-}$ (superoxide), $O _{2}^{2-}$ (peroxide)
Which one of the following species does not exist under normal conditions ?