Changes of Matter Quiz
Questions: 16 · 10 minutes
1. An ice cube melts in a glass without reacting with anything. Why is this classified as a physical change?
The water molecules break apart into hydrogen and oxygen.
The substance remains water even though its state changes.
Melting permanently changes the substance's chemical properties.
The liquid formed has more mass than the original ice.
2. During heating, a pure substance reaches its melting point and its temperature remains constant for a time even though energy is still being added. Where does that energy primarily go?
It creates additional matter inside the sample.
It causes the particles to stop moving.
It converts the substance into a new chemical element.
It helps overcome attractions between particles as the solid becomes liquid.
3. A candle is burning. Which description correctly identifies both a physical and a chemical change?
Both melting and combustion are chemical because heat is involved.
Wax melting is chemical, while light production is physical.
Both melting and combustion are physical because the candle becomes smaller.
Wax melting is physical, while wax vapor reacting during combustion is chemical.
4. Frost forms when water vapor changes directly into ice on a very cold surface. What is this change called?
Freezing
Deposition
Sublimation
Condensation
5. A shallow puddle disappears gradually on a warm, breezy day even though the water never boils. Which process occurred?
Condensation throughout the liquid
Evaporation from the water's surface
Sublimation from liquid to gas
Melting caused by moving air
6. Dry ice changes directly from a solid into carbon dioxide gas. What is this phase change called?
Sublimation
Deposition
Condensation
Freezing
7. A mixture contains dry sand and iron filings. Which method separates the substances without changing either one's chemical identity?
Using a magnet to attract the iron filings
Adding acid to dissolve the iron
Heating the mixture until the iron melts
Burning the mixture until the sand remains
8. A sealed container holding 100 grams of ice is allowed to warm until all the ice melts. What will the container and its contents weigh afterward?
More than 100 grams, because the ice absorbs thermal energy.
Less than 100 grams, because liquids have less mass than solids.
100 grams, because melting does not change the total mass in the sealed system.
It cannot be determined because liquid water has no fixed shape.
9. What happens to the particles of liquid water as the water freezes?
They stop moving completely and lose all energy.
They lose kinetic energy and become arranged in more fixed positions.
They change into a different type of molecule.
They gain kinetic energy and spread much farther apart.
10. An aluminum can is crushed into a compact shape. Why is crushing considered a physical change?
Its shape and volume change, but it remains aluminum.
The can loses all of its original physical properties.
The aluminum atoms become a new kind of atom.
Crushing causes aluminum to react chemically with itself.
11. A reaction takes place in an open beaker, and the measured mass afterward is lower than before. Which explanation best fits conservation of mass?
Some atoms were destroyed during the reaction.
Chemical changes do not obey conservation of mass.
The products naturally contain less matter than the reactants.
A gaseous product likely escaped from the open beaker before the final measurement.
12. Which statement correctly compares boiling with evaporation?
Evaporation forms a new substance, while boiling does not.
Boiling is a chemical change, while evaporation is a physical change.
Boiling occurs throughout a liquid at its boiling point, while evaporation occurs at the surface over a range of temperatures.
Evaporation occurs throughout a liquid, while boiling occurs only at the surface.
13. A student mixes vinegar and baking soda in a flask. The mixture rapidly produces a gas, and substances with new properties remain. What is the best conclusion?
A chemical change occurred because new substances were produced.
Only a phase change occurred because gases are always produced by boiling.
A physical change occurred because both starting materials are still unchanged.
No change of matter occurred because the total mass was conserved.
14. Water droplets form on the outside of a cold bottle on a humid day. Which change produced the droplets?
Liquid water from inside the bottle passed through the bottle wall.
Liquid water in the air froze onto the bottle.
The bottle material chemically changed into water.
Water vapor in the air condensed into liquid water.
15. Which observation most clearly indicates that iron rusting is a chemical change?
The iron can be shaped into a thin sheet.
The iron becomes warmer when left in sunlight.
A new substance with different properties forms on the iron.
The iron occupies space and has mass.
16. A student dissolves sugar in warm water and later recovers the sugar by evaporating the water. What does this best demonstrate?
Sugar and water formed a new chemical compound.
The sugar was destroyed when it became invisible.
Dissolving the sugar was a physical change.
Evaporation converted the water into sugar.