What is the Difference Between Paired and Unpaired Electrons?

The difference between paired and unpaired electrons lies in their arrangement and magnetic properties.

Paired electrons:

• Occupy the same orbital in an atom.
• Have opposite spins, as dictated by the Pauli exclusion principle.
• Cause the diamagnetism of atoms.

Unpaired electrons:

• Occupy atomic orbitals singly, rather than as part of an electron pair.
• Have a magnetic dipole moment, unlike electron pairs with opposite spins.
• Cause paramagnetism, ferromagnetism, and antiferromagnetism in elements with unpaired electrons.

Unpaired electrons are relatively rare in chemistry, as the formation of electron pairs is often energetically favorable. The most stable examples of unpaired electrons are found on the atoms and ions of lanthanides, where the incomplete f-shell does not interact very strongly with the environment. The ions with the largest number of unpaired electrons are Gd^3+ and Cm^3+ with seven unpaired electrons each.

In summary:

• Paired electrons occur in electron pairs and cause diamagnetism.
• Unpaired electrons occur singly and cause paramagnetism, ferromagnetism, or antiferromagnetism depending on the specific chemical environment.

Comparative Table: Paired vs Unpaired Electrons

The main difference between paired and unpaired electrons lies in their arrangement in atomic orbitals. Here is a table summarizing the key differences between paired and unpaired electrons:

Paired electrons always occur as a couple of electrons, while unpaired electrons occur as single electrons. The paired electrons cause the diamagnetism of atoms, whereas the unpaired electrons cause paramagnetism. These differences can be observed in the electron configuration of atoms, which reveals the arrangement of electrons in different energy levels.