States of Matter — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
A liquid has a definite shape and a definite volume.
Corrected: A solid has a definite shape and a definite volume.
A solid is the state of matter that holds both its shape and its volume. A liquid keeps its volume but flows to match the container, so the sentence has to describe a solid instead.
2. Fix the sentence:
A gas has a definite volume but no definite shape.
Corrected: A liquid has a definite volume but no definite shape.
Gas spreads out and has no fixed volume, so the sentence does not fit a gas. A liquid is what holds a definite volume while still changing shape to match the container.
3. Fix the sentence:
Ice is an example of a liquid.
Corrected: Ice is an example of a solid.
Ice is frozen water with a hard, fixed shape, which is exactly how a solid behaves. Liquids flow and change shape, so ice belongs in the solid group.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The three states of matter are solid, liquid, and gas.
Solid, liquid, and gas make up the three everyday states of matter, so gas completes the list. Air and steam are familiar examples of this third state.
2. A solid keeps its shape even when you move it to a new container.
Because a solid has tightly packed particles that stay in place, its outline does not change when you carry it around. That fixed outline is what we call its shape.
3. Water vapor in the air is an example of a gas.
Water vapor is water spread out into invisible particles drifting in the air, with no fixed shape or volume. That description matches a gas.
4. All matter takes up space and has mass.
Anything that counts as matter takes up room and contains a measurable amount of stuff. The amount of stuff in an object is its mass.
Part C: True or False?
Read each statement. Circle True or False.
1. A solid has a definite shape and a definite volume.
True False
True. The particles in a solid are locked into place, so a solid keeps both its shape and the amount of space it takes up no matter where you set it.
2. A gas fills the entire container it is placed in.
True False
True. Gas particles spread out in every direction and keep moving until they meet the walls, so a gas always fills whatever container is holding it.
3. A liquid has a definite shape like a solid.
True False
False. A liquid takes the shape of whatever container it sits in, while only a solid holds a definite shape on its own.