Year 9 - Understanding Matter and Changes (level 8)

What is a pure substance?

• A mixture of different elements and compounds

• A substance made of only one type of particle

• A solution of two or more substances

• A combination of gases

Which of the following is an example of a chemical change?

• Melting of ice

• Dissolving sugar in water

• Rusting of iron

• Boiling water

What is the main difference between a compound and a mixture?

• Compounds are made of one type of atom, mixtures are not

• Compounds have a fixed composition, mixtures do not

• Mixtures are pure substances, compounds are not

• Compounds can be separated by physical means, mixtures cannot

Which of the following properties is NOT explained by the particle model of matter?

• Density

• Viscosity

• Colour

• Compressibility

What happens to the particles in a substance when it is heated?

• They move slower

• They move faster

• They stop moving

• They become larger

Which of the following is a sign of a chemical reaction?

• Change in shape

• Change in temperature

• Change in size

• Change in state

What is the process called when a solid changes directly into a gas?

• Melting

• Freezing

• Sublimation

• Condensation

Which of the following best describes a solution?

• A pure substance

• A homogeneous mixture

• A heterogeneous mixture

• A compound

What is the term for the resistance of a liquid to flow?

• Density

• Viscosity

• Compressibility

• Diffusion

Which gas is commonly tested using a glowing splint?

• Carbon dioxide

• Oxygen

• Hydrogen

• Nitrogen