Question

Of ${\mathbf{N}}_{\mathbf{2}}$, ${\mathbf{O}}_{\mathbf{2}}$ and ${\mathbf{F}}_{\mathbf{2}}$, none has an electric dipole moment, but one does have a magnetic dipole moment, which one, and why?

(Refer to figure 10.10)

Short answer

Here, O₂ has a dipole moment.

Step-by-step solution

Dipole moment’s definition

The polarity of the system is called the electric dipole moment. The electric dipole moment is a measure of the separation of positive and negative charges in a system.

The magnetic dipole moment is used to measure the tendency of an object to interact with an external magnetic field.

Explanation of why O2  molecule has a magnetic dipole momentum

Oxygen O₂ has a magnetic dipole momentum molecule because it has two outermost electrons that spin that are unpaired in $\pi \times 2p$. In nitrogen N₂ and fluorine F₂ molecules, the electrons have spins in opposite pairs, and so the magnetic moment cancels each other.

Hence, the molecule oxygen O₂ molecule has a magnetic dipole moment.