Is Oxygen Paramagnetic or Diamagnetic?

Answers:- Oxygen is mainly paramagnetic. The fundamental reason oxygen is paramagnetic is that it has two unpaired electrons in its last molecular orbital. If you examine the oxygen molecule’s molecular orbital diagram, this can be demonstrated. Oxygen is a diradical with two unpaired electrons that have the same spin if we fill each orbital according to Hund’s rule. While this is happening, if you examine electrons, you will find that they not only orbit the atom in their orbital but also have a propensity to spin and so produce a magnetic field. Therefore, when unpaired electrons are present, as they are in oxygen, they spin in the similar direction, increasing the magnetic field effect and giving O2 its paramagnetic property.