Solid, Liquid, Gas
3 Minutes
States of matter for kids: learn what matter is, how tiny molecules are, and what makes solids, liquids, and gases. A short science lesson in English.
- The thirsty crow story and comparing pebbles with sugar in water
- How tiny atoms and molecules form all matter around us
- Why the gaps between molecules create solids, liquids, and gases
What this lesson teaches
Matter is everything around us, made up of tiny building blocks called atoms and molecules. Whether matter exists as a solid, a liquid, or a gas depends on the size of the gaps between these molecules.
How tiny molecules are
All matter, including everyday objects, machines, and living beings, is formed by atoms and molecules coming together. If a piece of paper is torn in half repeatedly until it cannot be split any further, that tiny particle is an atom. Molecules are so small that the thickness of a single sheet of paper contains more than a million of them. A tiny dot made by a ballpoint pen holds over 200,000 molecules, which would reach half the height of Mount Everest if stacked like five-rupee coins.
Properties of molecules
- Molecules that attract each other pull very close together, while those that do not attract stay far apart.
- There is always a gap between molecules, no matter how close or far apart they are.
- The distance or gap between molecules determines whether matter exists as a solid, a liquid, or a gas.
- Matter also has two fundamental properties, which are mass and volume.
States of matter and molecular gaps
- In a solid, such as a piece of ice, the gap between molecules is very small.
- In a liquid, such as water, the gap between molecules is a little bigger.
- In a gas, such as water vapor, the gap between molecules is much larger.
The pebble and sugar experiment
Dropping solid pebbles into a bottle pushes the water level higher, which helps a thirsty crow drink. Adding sugar to water does not make the water level rise in the same way. This difference happens because of the way matter is structured from tiny molecules and how those molecules behave together.