Why is `O_2` molecule paramagnetic ?

Which O_2 molecules is pargmanetic. It is explained on the basis of:

Which of the following is paramagnetic?

Which of the following is paramagnetic?

The shape of SO_2 molecule is

Which of the following sets of ions contain only paramagnetic ions

Which one of the following sets CORRECTLY represents the increase in the paramagnetic property of the ions?

At what temperature will the R.M.S. velocity for H_2 molecule-be same as that for O_2 molecule at 127° C?

Why is an antibody molecule is represented as H_2L_2 ?

Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled ?