Question

$O_2$ is paramagnetic in nature because it has two unpaired electrons.
if true enter 1, else enter 0.

• A. 1

Answer 1

The correct option is A 1
Gaseous oxygen is paramagnetic also but is moving too fast to be affected by the magnets. The reason that it is paramagnetic is because the oxygen molecule has two unpaired electrons. Electrons not only go around the atom in their orbitals, they also spin, which creates a magnetic field. Two electrons can occupy each s orbital, while 6 electrons can occupy each p orbital. Following the Exclusion Principle, two electrons will fill both the 2s and 2s* orbitals, 6 electrons will fill the 2p orbital, and that leaves 2 electrons to fill the 2p* orbital. These two electrons will only partially fill this orbital, and will have parallel spins. Since the rest of the electrons are all paired, the remaining two electrons in the 2p* orbital give the diatomic molecule a net total spin (it does not matter if they are 1/2 or -1/2 spins, they will both be the same). Since there is a net spin, O2 is paramagnetic.