For magnetic properties of oxides:
O\(^{2-}\) and O\(_2^{2-}\) ions are diamagnetic due to paired electrons.
O\(_2^-\) ions are paramagnetic due to the presence of unpaired electrons.
1. Li\(_2\)O (Lithium Oxide): Contains O\(^{2-}\) ions, which have a completely filled electronic configuration.
Magnetic Behaviour: Diamagnetic.
2.Na\(_2\)O\(_2\) (Sodium Peroxide): Contains O\(_2^{2-}\) ions, which also have a completely paired electronic configuration.
Magnetic Behaviour: Diamagnetic.
3. KO\(_2\) (Potassium Superoxide): Contains O\(_2^-\) ions, which have one unpaired electron.
Magnetic Behaviour: Paramagnetic.
Final Answer: \((4)\) Diamagnetic, Diamagnetic, Paramagnetic.
Wave propagates whose electric field is given by \(\mathbf{E} = 69 \sin(\omega t - kx)\,\hat{j}\). Find the direction of magnetic field.
