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Physical Chemistry

Paramagnetic

Definition and meaning of Paramagnetic in chemistry.

Paramagnetic is an adjective that describes a substance with a specific magnetic weakness. These materials are pulled slightly toward any outside magnetic field. This happens because they contain unpaired electrons inside their atomic structure.

In more detail

To understand paramagnetic behavior, you must look at how electrons arrange themselves. Electrons fill up spaces called orbitals around an atom. Every electron acts like a tiny spinning magnet.

Most atoms have all their electrons matched up in pairs. When two electrons share an orbital, they spin in opposite directions. This perfect matching cancels out their magnetic push and pull.

Materials with only paired electrons push away from magnets. But a paramagnetic substance has at least one lone electron in some orbitals. These lone electrons do not have a partner to cancel their spin.

Their tiny magnetic forces remain constantly active. When you bring a real magnet close, these lone electrons react. They twist around to face the exact same direction as the real magnet.

This group effort creates a gentle pulling force toward the magnet. The pulling force grows stronger if the substance has more unpaired electrons. A common mistake is thinking paramagnetic things are like permanent refrigerator magnets.

Refrigerator magnets are ferromagnetic and hold their charge forever. Paramagnetic items only act magnetic while another magnet is right next to them. If you take the external magnet away, the electrons go back to pointing randomly.

Heat also ruins the pulling effect. Hot atoms bounce around and mess up the neat lines of electrons.

Key facts

FieldPhysical Chemistry
Core causeOne or more unpaired electrons
Resulting behaviorWeak attraction to magnetic fields
Difference from ferromagnetismDoes not keep a permanent magnetic charge
Temperature ruleMagnetic strength drops as temperature rises
Common examplesOxygen gas and transition metal ions
Example

Transition metal ions are often highly paramagnetic. For instance, an iron ion with a plus three charge is written as Fe3+. This specific ion has five unpaired electrons in its outer d-orbitals. This unusually large number of lone electrons makes the iron ion strongly attracted to nearby magnetic fields.

Frequently asked questions

How is a paramagnetic material different from a diamagnetic material?

Paramagnetic materials have unpaired electrons and are pulled toward magnets. Diamagnetic materials have only paired electrons and are pushed away by magnets.

Why does heat make paramagnetic materials less magnetic?

High temperatures cause the atoms to vibrate violently. This violent motion stops the unpaired electrons from lining up with the magnet.

Can a paramagnetic material hold a magnetic charge?

No. The weak magnetic attraction vanishes the moment you move the external magnet away from the material.

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