The Department of Chemistry at the University of Illinois

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Magnetic liquid oxygen

powerful magnet with liquid oxygen sticking to poles

Why is liquid oxygen attracted to a magnet?


This picture shows a powerful magnet.

pouring liquid nitrogen on poles of magnet

Let's pour liquid nitrogen on the poles of the magnet and observe its behavior. Liquid nitrogen is kept cold in this insulated glass flask called a Dewar.

Click on the small pictures to see the video.

thumbnail pouring liquid nitrogen on poles of magnet

Liquid nitrogen does not stick to the poles of the magnet.

magnet and glass tube with liquid oxygen, pale blue color

The glass tube contains liquid O2. The liquified gas is pale blue in color.

thumbnail magnet and ltube of liquid oxygen

Liquid oxygen is attracted to and actually sticks to the poles of the magnet. The liquid O2 remains between the poles until it evaporates in the warm atmosphere.

Lewis structure of oxygen

Liquid O2 sticks to a magnet while liquid N2 does not because of differences in electron distribution. One possible Lewis structure for O2 shows an unpaired electron on each oxygen atom. Molecules with unpaired electrons are called paramagnetic and exhibit magnetic properties.

Lewis structure of nitrogen

The Lewis structure of N2 does not have unpaired electrons. Molecules with no unpaired electrons that do not exhibit magnetic properties are called diamagnetic.

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Chemistry at Illinois University of Illinois at Urbana-Champaign