Paramagnetic
Definition and meaning of Paramagnetic in chemistry.
Paramagnetic describes a substance that is weakly attracted to external magnetic fields due to unpaired electrons in its atoms or molecules. Unlike ferromagnetic materials, paramagnetic materials do not retain permanent magnetization and lose their magnetic attraction when the external field is removed.
In more detail
Paramagnetism arises in atoms or molecules that contain unpaired electrons in their electron configuration. These unpaired electrons create small magnetic dipoles that align with an external magnetic field, resulting in a net weak attraction. The strength of this attraction depends on the number of unpaired electrons and is typically weak because the magnetic moments are randomly oriented in the absence of an external field. Paramagnetism follows Curie's law and generally decreases with increasing temperature.
Key facts
| Cause | Unpaired electrons |
|---|---|
| Field | Physical Chemistry |
| Behavior | Weakly attracted to magnetic fields |
| Common Example | O2 |
Oxygen gas (O2) is paramagnetic due to two unpaired electrons in its molecular orbital diagram. Transition metal ions such as Fe3+ and Mn2+ are also paramagnetic.
Frequently asked questions
How is paramagnetism different from diamagnetism?
Paramagnetic materials contain unpaired electrons and are attracted to magnetic fields. Diamagnetic materials have all electrons paired and are slightly repelled by magnetic fields.
Why does paramagnetism decrease at higher temperatures?
At higher temperatures, thermal motion disrupts the alignment of magnetic dipoles with the external field, reducing the net magnetization according to Curie's law.