States of Matter — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Particles in a solid vibrate in place but do not move around.
Solid particles are packed so tightly together that they can only vibrate back and forth in place. Unlike liquid or gas particles, they cannot slide past each other or travel freely.
2. A gas has no definite shape and no definite volume.
Gas particles spread out to fill any space available, so a gas has no definite shape or volume. A small puff of air will expand to fill an entire room.
3. When liquid water boils, it turns into water vapor.
Boiling adds enough heat to turn liquid water into water vapor, which is water in the gas state. You can see the steam rising from a boiling pot as this change happens.
4. You can measure the mass of matter using a balance or scale.
Mass is the amount of matter in an object, and a balance or scale measures it. Everything made of matter — whether solid, liquid, or gas — has mass.
5. A metal spoon is a solid because it keeps its shape.
A metal spoon holds its shape whether it sits on a table or in a drawer. That fixed shape is what makes it a solid.
6. The change from gas to liquid is called condensation.
Condensation happens when gas particles cool down and come together to form a liquid. You see condensation when water droplets appear on a cold glass on a warm day.
7. Cooking oil poured into a bowl takes the shape of the bowl.
Cooking oil is a liquid, and liquids flow to match the shape of their container. Pour the same oil into a tall glass and it will take a completely different shape.
8. Temperature tells us how hot or cold something is.
Temperature measures how much heat energy something has. A high temperature means hot, and a low temperature means cold.
9. Particles in a solid are packed very tightly together.
Solid particles are packed tightly together in a fixed pattern, which is why solids hold their shape. Liquid and gas particles have more space between them.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Honey
→ Liquid that flows slowly
Solid
Wooden block
→ Solid
Gas
Oxygen
→ Gas
Liquid that flows slowly
Lemonade
→ Liquid that flows easily
Liquid that flows easily
Honey is a thick liquid that flows slowly, while lemonade is a thin liquid that flows easily. A wooden block is a solid with a fixed shape, and oxygen is a gas you breathe but cannot see.