States of Matter
Kindergarten · Science · Study Guide
Explore solids, liquids, and gases — the three states that all matter can be in!
Everything around us is made of matter — your toys, the air you breathe, and the juice you drink. Matter can exist in three main states: solid, liquid, and gas. The state of matter describes how tightly packed together its tiny building blocks are and whether it has a fixed shape.
A solid has a definite shape and does not pour or flow — think of a rock, a wooden block, or an ice cube. A liquid does not have its own shape — it takes the shape of whatever container you put it in. Water, milk, and juice are all liquids. A gas spreads out to fill any space — you cannot see most gases, but air is a gas and we breathe it every day!
Matter can change states when it gets heated or cooled. Ice (a solid) melts into water (a liquid) when it gets warm. Water boils into steam (a gas) when it gets very hot. Steam turns back into water droplets when it cools down. This is why puddles disappear on a sunny day!
| State | Shape | Examples |
|---|---|---|
| Solid | Has its own shape | Rock, ice, wood, crayon |
| Liquid | Takes container's shape | Water, juice, milk, honey |
| Gas | Fills any space | Air, steam, bubbles in soda |
Key terms
- Matter
- Everything that takes up space and has weight — solids, liquids, and gases.
- Solid
- A state of matter with a definite shape that does not flow — like a rock or ice cube.
- Liquid
- A state of matter that flows and takes the shape of its container — like water or juice.
- Gas
- A state of matter that spreads out to fill any space — like air or steam.
- Melt
- To change from a solid into a liquid when heated — like ice turning to water.
Flashcards
- Solid
- A state of matter with a fixed shape — like rocks, wood, and ice.
- Liquid
- A state of matter that flows and takes the shape of its container.
- Gas
- A state of matter that spreads out to fill any space, like air.
- Matter
- Everything that takes up space — solids, liquids, and gases are all matter.
- Melt
- When a solid turns into a liquid because of heat.
- Evaporate
- When a liquid turns into a gas — like puddles disappearing on a sunny day.
Practice questions
Which state of matter has its own definite shape?
- Liquid
- Gas
- Solid
- Steam
Show answer
Answer: Solid
Solids have a fixed, definite shape because their particles are tightly packed and cannot flow freely.
Air is an example of a gas.
Show answer
Answer: True
Air is a mixture of gases — mainly nitrogen and oxygen — that we breathe and that surrounds the Earth.
What happens to ice when it gets warm?
- It gets harder
- It melts into water
- It turns into gas instantly
- It floats away
Show answer
Answer: It melts into water
When ice absorbs heat energy, its particles move faster and break apart from their rigid arrangement, turning it into liquid water.
A liquid has its own fixed shape.
Show answer
Answer: False
Liquids do not have a fixed shape — they take the shape of whatever container holds them.
The three states of matter are solid, liquid, and ___.
Show answer
Answer: gas
The three main states of matter are solid (fixed shape), liquid (flows), and gas (fills any space).
Fun facts
- Water is one of the few things on Earth that we regularly see in all three states — ice, water, and steam!
- The air around you is a mix of invisible gases — mostly nitrogen and oxygen.
- Lava from a volcano is melted rock — a super-hot liquid that turns solid when it cools!
Get a personalized course on States of Matter built around your child.