Question

Why does the presence of an unpaired electron make a transition metal ion paramagnetic?

Answer 1

1. An unpaired electron has a magnetic moment because it spins and creates a tiny magnetic field.
2. This spinning electron acts like a small magnet (micromagnet) that can align with an external magnetic field.
3. When a transition metal ion has unpaired electrons, these individual magnetic moments add up, leading to attraction by a magnetic field.
4. Ions with more unpaired electrons show stronger paramagnetism because the overall magnetic moment is greater.
5. Paired electrons have opposite spins whose magnetic effects cancel out, making ions with all paired electrons diamagnetic (not attracted to magnetic fields).

Thus, paramagnetism in transition metal ions is due to the presence of one or more unpaired electrons whose magnetic moments cause attraction to magnetic fields.