States of Matter
What are the three states of matter?
Solid, liquid, gas.
What change of state happens when a solid becomes a liquid?
Melting
What are the tiny building blocks that make up all matter?
Atoms
Is melting ice a physical or chemical change?
Physical
What is the first step of the scientific method?
Ask a question.
Which state of matter has particles that are tightly packed and hold their shape?
Solid
What change of state happens when a liquid loses heat and becomes solid?
Freezing
True or False: Atoms can be seen with your eyes.
False.
What do we need to see them?
What type of change creates a new substance?
Chemical change.
What is a hypothesis?
A possible answer to the question, what we think is going to happen/what we think the answer to the question is.
Which state of matter takes the shape of its container but keeps its volume?
Liquid
What is it called when a liquid gains heat and becomes a gas?
Evaporation
Why do solids keep their shape while liquids and gases do not, based on how their particles are arranged?
Because solid particles are tightly packed in fixed positions, while particles in liquids and gases are not fixed and can move around.
Is cutting paper a physical or chemical change? Why?
Physical — it’s still paper.
What do we call the part of an experiment that stays the same?
Controls
Which state of matter has particles that are far apart and move very fast?
Gas
What do we call it when a gas loses heat and becomes a liquid?
Condensation
What happens to particle spacing AND movement when heat is removed from a gas?
The particles slow down and move closer together, which can cause the gas to change into a liquid (condensation).
Explain the differences between a chemical and physical change and list an example of each.
A physical change changes the way something looks, but it is still the same substance. It can usually be reversed.
Examples: cutting paper, melting ice, breaking a stick.
A chemical change makes a new substance. It is usually permanent and cannot be undone.
Examples: rusting metal, baking a cake, burning wood.
Name the three possible outcomes of a conclusion.
1. Hypothesis is supported
2. Hypothesis is not supported
3. More information needed
How do the particle arrangements and movements in solids, liquids, and gases explain why each state has a different shape and volume?
Solids have tightly packed particles that only vibrate, so they keep a fixed shape and volume.
Liquids have close particles that can slide past each other, so they change shape but keep the same volume.
Gases have particles that are far apart and move quickly, so they have no fixed shape or volume.
Name the change of state where a solid turns directly into a gas.
Sublimation
Explain how particle movement helps us understand why some materials expand when heated and contract when cooled.
When heated, particles move faster and spread farther apart, causing the material to expand. When cooled, particles slow down and move closer together, causing the material to contract.
Name 4 out of the 5 signs that a chemical change has happened.
Colour change, odour change, temperature change, gas formation, formation of a precipitate.
Why do scientists record their procedures and observations carefully during an experiment?
So the experiment can be repeated accurately, the results can be checked, and others can verify or repeat the investigation to see if they get the same outcome.