States of Matter
This state of matter holds its shape and does not take the shape of its container.
What is a solid?
Molecules in this state move in place but stay close together.
What is a solid?
Temperature measures the average _____ energy of molecules.
What is kinetic?
A phase change is a change in a substance’s _____ of movement.
What is freedom (of movement)?
All matter is made of tiny pieces called _____.
What are atoms?
This state of matter flows and takes the shape of its container.
What is a liquid?
Molecules in this state move around each other but not far apart.
What is a liquid?
What happens to molecular movement when energy is added to a substance?
It increases.
Phase changes involve a change you can see at the _____ scale.
What is the macroscale?
The idea that all matter is made of atoms is called the _____ theory.
What is the atomic theory?
This state of matter has no visible shape and fills its container.
What is a gas?
Molecules in this state move freely and far apart.
What is a gas?
What happens to molecular movement when energy is removed from a substance?
It decreases.
What scale explains why a phase change happens, even though we can’t see it?
What is the molecular scale? Or microscopic scale.
Why do scientists use models to study atoms?
Because atoms are too small to see.
Why does a solid keep its shape at the molecular level?
A solid keeps its shape because its molecules are tightly packed and only vibrate in place.
Explain why liquids can flow but solids cannot.
Liquid molecules move around each other; solid molecules do not.
Why can adding energy cause a substance to change state?
Adding energy increases the movement of molecules. As they move faster, they can break free from their current arrangement, causing the substance to change from one state (like solid) to another (like liquid or gas).
What happens during melting, and how does this phase change affect the arrangement of molecules?
During melting, a solid gains heat and changes into a liquid. The molecules start moving faster and slide past each other, causing the solid to lose its rigid structure.
What makes different substances have different properties?
Different substances have different properties because of the types of atoms they are made of and how those atoms are arranged. This affects things like color, hardness, and how they react with other substances.
Which state of matter has molecules that can move apart and fill any container, and how does that affect its shape?
Gas - The molecules move freely and spread out to fill the shape of the container.
Rank solids, liquids, and gases from least to most freedom of movement.
Solid → Liquid → Gas
How does adding heat energy affect the temperature and state of a substance?
Adding heat makes the molecules move faster, which raises the temperature. If enough heat is added, it can change the substance’s state, like from a solid to a liquid.
Why does water evaporate faster on hot days than on cold days?
Water evaporates faster on hot days because the heat makes the water molecules move faster, allowing them to escape into the air more easily.
What does a chemical formula show?
A chemical formula shows the types and numbers of atoms in a molecule of a substance. For example, Hâ‚‚O tells you there are 2 hydrogen atoms and 1 oxygen atom in a water molecule.