Everything around us, from the chair you are sitting on to the air you breathe, is made up of something scientists call matter. Understanding matter is like finding the ultimate secret ingredient for everything in the universe. This simple concept helps explain how everything you see, touch, and even can’t see is put together.
What Is Matter
Matter is anything that takes up space (volume) and has weight (mass). This means a giant rock is matter, but so is a tiny speck of dust, because both possess mass and volume.
Even things that seem empty, like the air in a balloon, are full of matter. A filled balloon has more mass than an empty one, proving that gas takes up space. All matter is constructed from incredibly small pieces, often called “tiny building blocks.” These building blocks are atoms and molecules, which are completely invisible to the eye.
The Three Main Forms of Matter
Matter can be found in three common states: solid, liquid, and gas. These states are defined by how the tiny building blocks (atoms and molecules) are arranged. The way the particles behave in each state determines the matter’s overall properties.
In a solid, such as an ice cube or a wooden block, the building blocks are packed tightly together in a fixed, orderly pattern. They can only wiggle or vibrate in their spots. This arrangement is why a solid object keeps its specific shape and volume, regardless of the container.
A liquid, such as water or milk, has building blocks that are close together but are not held in a fixed position. These particles can slide and tumble past one another, allowing the liquid to flow easily. This movement means a liquid will take the shape of any container it is poured into, while still keeping the same volume.
In a gas, the tiny building blocks are very far apart and move around quickly and randomly. There is a lot of empty space between the particles, allowing them to expand and fill any container they are put into. The air you breathe is a gas, and it has no set shape or volume because its particles are constantly flying in all directions.
How Matter Changes
Matter can change its state through a physical change, where the tiny building blocks simply rearrange themselves. For example, when an ice cube is left out, it changes from a solid to a liquid through melting. The heat gives the tightly packed water particles more energy, allowing them to move fast enough to break free from their fixed positions.
If you were to put that liquid water back into a freezer, it would change back into a solid through freezing. The cold temperature slows the particles down until they lock back into a rigid structure, forming ice again. This change is physical because the substance itself is still water, or H₂O, in both the solid and liquid forms.
A liquid can also become a gas through boiling or evaporation. When you boil water on a stove, the particles gain so much energy that they escape the liquid completely and float away as a gas (steam). In all these physical changes, the particles remain the same water molecules; they are only arranged differently and possess different amounts of movement.
What Is NOT Matter
Not everything you experience is considered matter. For something to be matter, it must have both mass and volume. Things that do not qualify as matter are usually forms of energy or abstract concepts.
Light from the sun, the warmth you feel from a fire, and the sound of music are all examples of energy, not matter. Energy does not have mass and does not take up space in the same way a book or a ball does.
Ideas, thoughts, feelings like happiness or sadness, and even gravity are also not matter. These concepts are real, but you cannot weigh them on a scale or place them in a container, so they do not fit the scientific definition of having mass and volume.