Van der Waals force facts for kids

Geckos can stick to walls and ceilings because of van der Waals forces.

A molecule with a difference in charge, from end to end.

In chemistry, a van der Waals' force is a type of intermolecular force. Think of intermolecular forces as tiny, invisible glues that hold molecules together. Van der Waals forces are the weakest kind of these glues. They are named after a Dutch scientist named Johannes Diderik van der Waals (1837–1923).

What are Van der Waals Forces?

Van der Waals forces are weak attractions between molecules. They are not as strong as the chemical bonds that hold atoms together inside a molecule. But these forces are still very important! They help explain why many things in our world behave the way they do.

How Do They Work?

Every molecule has tiny, negatively charged electrons moving around. These electrons are always moving, so sometimes there are more electrons on one side of a molecule than the other. This creates a tiny, temporary difference in charge. One side becomes a little bit negative (δ^-), and the other side becomes a little bit positive (δ⁺). These are called partial charges.

When two molecules with these partial charges get close, the slightly positive part of one molecule is attracted to the slightly negative part of another. It's like tiny magnets pulling them together! This attraction is the van der Waals force.

Why Are They Important?

Even though they are weak, van der Waals forces add up. They play a big role in many areas of science:

• They help enzymes (special proteins in your body) do their jobs.
• They affect how plastics and other materials behave.
• They are key in nanotechnology, which deals with super tiny things.
• They help explain why Geckos can stick to walls and ceilings! Their feet have millions of tiny hairs that create many van der Waals attractions with the surface.
• These forces also help decide if a substance will dissolve in water or other liquids. This is called its solubility.

Images for kids

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  Rain water on a leaf. Van der Waals forces help drops form.

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  A gecko climbing a glass surface.

See also

In Spanish: Fuerzas de Van der Waals para niños