Sticky facts for kids

Stickiness is a cool property that makes things cling or hold onto each other. Think about how glue works, or how a gecko can walk on walls! It's all about how surfaces interact.

What is Stickiness?

Stickiness is the quality of something being able to attach to another surface. It's like a special kind of grip. Some things are naturally sticky, like honey. Other things are made to be sticky, like tape or glue. This property is very useful in our daily lives.

How Things Stick Together

Things stick together because of tiny forces between their atoms and molecules. When two surfaces get very close, these forces can become strong enough to hold them. The type of surface and how smooth it is can affect how sticky it feels.

Adhesion and Cohesion

There are two main ways things stick:

• Adhesion is when different types of things stick together. For example, glue sticking to paper is adhesion. Water drops sticking to glass is also adhesion.
• Cohesion is when the same type of thing sticks to itself. Water molecules sticking to other water molecules is cohesion. This is why water forms drops instead of spreading out completely.

Many sticky things use both adhesion and cohesion. Glue, for instance, needs to stick to the surface (adhesion) and also hold itself together (cohesion).

Why is Glue Sticky?

Glue is designed to be very sticky. It usually starts as a liquid. When it dries, its molecules form strong bonds with the surfaces it touches. These bonds are a type of adhesion. The glue itself also forms a strong, solid layer through cohesion. This combination makes glue very effective at holding things together. Different glues work in different ways, but they all rely on these basic principles.

Examples of Stickiness

Stickiness is all around us, from nature to inventions.

Sticky Notes

A sticky note is a small piece of paper with a special strip of weak glue on the back. This glue is designed to be sticky enough to hold the note in place, but also weak enough so you can easily remove it without tearing the paper or leaving a mark. This is a great example of controlled adhesion.

Sticky Plants and Animals

Nature has many examples of stickiness:

• Burrs are seeds from some plants that have tiny hooks. These hooks stick to animal fur or clothing, helping the plant spread its seeds.
• Geckos are lizards that can climb walls and ceilings. Their feet have millions of tiny hairs. These hairs create very weak forces with the surface, but because there are so many of them, they create a strong overall grip.
• Spider webs are incredibly sticky. The silk threads are covered in a special glue that traps insects.

Images for kids

• Post-it note pad.jpg

  A stack of sticky notes.