Read the first worked example with the solution open so the structure is clear.
Try the practice problems before revealing each solution.
Use the related concepts and background knowledge badges if you feel stuck.
What to Focus On
Core idea:Matter asks what the sample is, what property is being used, and whether a new substance is formed.
Common stuck point:Students often know a formula related to matter but skip the recognition step: Am I classifying matter or using properties, state, particle behavior, or mixture evidence to describe a sample? That leads to a correct-looking substitution attached to the wrong chemical model.
Sense of Study hint:Ask: Am I classifying matter or using properties, state, particle behavior, or mixture evidence to describe a sample?
Worked Examples
Example 1
easy
Define matter and give three examples of things that are matter and three that are not.
Matter is anything that has mass and occupies space (has volume).
Full solution
2
Examples of matter: water, air, iron ā all have measurable mass and volume.
3
Not matter: light, heat, sound ā these are forms of energy, not substances.
The distinction between matter and energy is fundamental in science. Matter can exist in different states (solid, liquid, gas) and can undergo physical and chemical changes.
Example 2
medium
Classify each as a physical or chemical property: (a) boiling point, (b) flammability, (c) color, (d) reactivity with acid.
Example 3
medium
Sort each into matter or not matter: rock, light, heat, juice, electricity.
Example 4
medium
A scientist says 'plasma is the fourth state of matter.' What does plasma look like in everyday life?
Example 5
hard
A sealed jar of water is weighed before and after the water freezes. Will the total weight change?
Example 6
hard
A candle burns completely. The wax seems to vanish. Where did the matter go?
Example 7
hard
Two identical jars: one has air, the other is a vacuum. Which weighs more, and by how much (qualitatively)?
Example 8
challenge
Einstein's E=mc2 says mass and energy are related. Does this mean energy IS matter?
Practice Problems
Try these problems on your own first, then open the solution to compare your method.
Example 1
easy
Is air considered matter? Justify your answer.
Example 2
hard
A student claims that heat and light are forms of matter because they can be detected and measured. Evaluate this claim using the definition of matter.
Example 3
easy
Is air matter? Answer yes or no and give the two-part reason.
Example 4
easy
Classify heat (thermal energy): is it matter? Answer yes or no with a reason.
Example 5
easy
Is a single atom matter? Yes or no, and why?
Example 6
easy
Which of these is NOT matter: a rock, a cloud, sunlight, water?
Example 7
easy
A balloon is weighed empty, then weighed full of air. Which weighs more?
Example 8
easy
Define matter in one sentence.
Example 9
easy
Is a beam of laser light matter? Explain briefly.
Example 10
easy
Steam, liquid water, and ice are all the same substance. Are all three matter?Ice, liquid water, and steam: all three are the same substance in different states
Example 11
medium
A sealed flask of gas reads 250 g on a balance. After the gas escapes, the empty flask reads 248 g. What was the mass of the gas, and what does this prove?
Example 12
medium
Sort into matter vs energy: (a) electricity, (b) carbon dioxide, (c) sound, (d) salt.
Example 13
medium
A student claims 'a vacuum is matter because it occupies space.' What is wrong with this claim?
Example 14
medium
Two identical jars: one holds 1 L of helium, the other 1 L of air. Both are matter, but how do their masses compare and why?
Example 15
medium
Classify each as matter or not: a magnetic field, a copper wire, a thought, dust.
Example 16
medium
If you compress a gas into half its volume in a rigid cylinder, does its mass change? Is it still matter?
Example 17
medium
A candle burns and seems to 'disappear.' Did the matter vanish? Explain using conservation of mass.
Example 18
medium
Which has more matter: a 5 kg block of foam or a 5 kg block of steel?
Example 19
medium
Plasma in a neon sign: is it matter? Justify.
Example 20
challenge
A sealed 500 g container holds wood and oxygen. The wood burns completely, producing ash, CO2, and water vapor that stay sealed inside. What does the balance read afterward, and what principle guarantees it?
Example 21
challenge
Explain why the statement 'matter can be created or destroyed in ordinary chemical reactions' is false, and state the correct principle.
Example 22
challenge
A 1.0 L sealed bottle of air is heated so the gas wants to expand but cannot. State whether each changes: (a) mass of gas, (b) number of particles, (c) volume. Then explain whether it is still matter.
Example 23
easy
Is a wooden block matter?
Example 24
easy
Is sound matter? Yes or no?
Example 25
easy
Name the three most common states of matter on Earth.The three most common states of matter on Earth
Example 26
easy
Which of these is matter: a thought, a sandwich, or a song?
Example 27
easy
Is water vapor (steam) matter?
Example 28
medium
A balloon is squeezed and becomes smaller. Did the matter inside change to something else?
Example 29
medium
What state of matter has a definite volume but takes the shape of its container?
Example 30
medium
Which property tells you how much matter is in an object?
Example 31
medium
Ice melts into water. Did the matter disappear?Ice melts into water ā does the matter disappear?
Example 32
medium
Which has more matter: a feather or a brick of equal volume?
Example 33
hard
Does an electron have mass? Is it matter?
Example 34
hard
Is the vacuum of outer space considered matter?
Example 35
hard
Why are heat and light not considered matter, even though they can transfer energy?