Lesson T6.1.1

T6.1.1 Conservation of mass in physical changes Quiz: KS3 Physics, Unit 6

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson T6.1.1, Conservation of mass in physical changes: 20 multiple choice questions for the KS3 Physics (National Curriculum), Unit 6: Matter and particles, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. In a physical change, what happens to the total mass of the substances involved?

    • It decreases
    • It depends on the temperature
    • It increases
    • It stays the same

  2. Which of these is a physical change?

    • Rusting of an iron nail
    • Cooking an egg until it sets
    • Burning wood to make ash
    • Melting ice into water

  3. When 20 g of ice melts in a sealed bag, what is the mass of the water produced?

    • 0 g
    • 25 g
    • 10 g
    • 20 g

  4. Why does an open bowl of water seem to lose mass as the water evaporates?

    • The water is destroyed by evaporation
    • Evaporation converts water into a lighter element
    • The water vapour escapes into the air, so it is not weighed
    • Gravity pulls the water out of the bowl

  5. When 50 g of salt dissolves completely in 200 g of water, what is the total mass of the solution?

    • 200 g
    • 150 g
    • 50 g
    • 250 g

  6. Which of these is a chemical change rather than a physical change?

    • Melting a block of wax
    • Dissolving sugar in tea
    • Freezing water into ice
    • Burning a piece of paper

  7. Which process turns a solid straight into a gas without becoming a liquid?

    • Sublimation
    • Dissolving
    • Condensation
    • Freezing

  8. Which change of state is caused by cooling a gas?

    • Boiling
    • Condensation
    • Sublimation
    • Evaporation

  9. A physical change is best described as one that:

    • Creates brand new substances and releases a lot of heat energy
    • Destroys some of the mass of the substance during the change
    • Changes the state or shape of a substance without making new substances
    • Always makes a gas that escapes from the substance into the air

  10. A student freezes water and then melts the ice. Which statement is correct?

    • The mass of the water is halved after it has been frozen solid
    • The mass of the water changes only at the moment it freezes
    • The mass of the water increases when the ice melts and expands
    • The mass of water is the same at the end as at the start

  11. Which statement about the mass of a dissolved substance is correct?

    • The dissolved substance turns into energy
    • The dissolved substance disappears completely
    • The dissolved substance is converted into water
    • The dissolved substance is still present in the solution

  12. A candle melts, then the wax solidifies again. What kind of change is this?

    • A change that creates a new element
    • A chemical change that cannot be reversed
    • A physical change that can be reversed
    • A change that destroys mass

  13. If 30 g of solid is heated and turns into a liquid, what is the mass of the liquid?

    • 15 g
    • 30 g
    • It depends on the colour
    • 60 g

  14. Why is the mass of a gas in a sealed container the same as before it was heated?

    • The container absorbs the gas's mass as it is heated up
    • Heat adds some extra mass to the gas as it warms up
    • No matter is added or removed, so mass is conserved
    • Gases always have zero mass whatever their temperature is

  15. Which of these is a physical change that is easy to reverse?

    • Burning a match
    • Rusting an iron gate
    • Melting an ice cube
    • Cooking an egg until it sets

  16. Sugar dissolves in water and the mass of the solution is measured. What does this show?

    • Dissolving creates new mass
    • The mass of sugar is destroyed
    • The solution is always heavier than the water alone
    • Mass is conserved when a substance dissolves

  17. What is the particle model used to explain when matter changes state?

    • Particles are destroyed in one state and then remade again
    • Particles become much larger in size when they are heated
    • Particles move differently and are arranged differently
    • Particles change into energy that is given out as heat

  18. Which measurement would show that mass is conserved during condensation?

    • Measuring only the temperature of the room as the water condenses away
    • Measuring only the volume of the vapour that rises from the water surface
    • Measuring the colour of the water as it condenses on the cold glass
    • Measuring the mass of the water before and after it condenses on a cold surface

  19. A block of metal is cut into pieces. The pieces are then weighed together. What is the total mass compared with the original block?

    • Half of the original
    • The same as the original
    • Less than the original
    • More than the original

  20. Which process is a physical change in which a liquid turns into a gas at its surface at any temperature?

    • Electrolysis
    • Combustion
    • Oxidation
    • Evaporation

All KS3 Physics quizzes