Year 8/9 Chemical Sciences Multi choice

Which of the following is a chemical change?

• Sawdust is produced from wood being cut by a power saw.

• Water freezes to form ice.

• Fireworks explode in a colourful light display.

• Juice is obtained from an orange.

Describe the particles in a solid.

• The particles in a solid are strongly bonded to each other so the solid has a definite shape.

• The particles in a solid are strongly bonded to each other so the solid does not have a definite shape.

• The particles in a solid are weakly bonded to each other so the solid has a definite shape.

• The particles in a solid are weakly bonded to each other so the solid does not have a definite shape.

Identify why gases are easily compressed.

• the particles can diffuse

• there is pressure between particles squashing them together

• there is great energy between the particles allowing them to change

• there is a lot of space between the particles

Recall the scientific term used to describe the process of a gas changing to a liquid.

• evaporation

• boiling

• condensation

• sublimation

A permanent colour change may be an indication that a chemical reaction has taken place. Identify which of the following is not an indication of a chemical reaction.

• sugar caramelising

• toast bread

• a glass breaking

• burning a match

As a solid object is heated, its particles:

• vibrate less rapidly and cause it to contract.

• vibrate more rapidly and cause it to expand.

• attract each other more, causing contraction.

• shrink in size so the gaps between them increase.