G7-SCI-L5 Physical and Chemical Changes

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

• Burning of wood
• Digestion of food
• Melting of ice cream
• Photosynthesis

What is the process called when a substance changes from a solid to a liquid?

• Evaporation
• Condensation
• Melting
• Freezing

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

• Dissolving sugar in water
• Cutting a piece of paper
• Burning of coal
• Stretching a rubber band

What is the product of the chemical reaction between magnesium and oxygen?

• Magnesium oxide
• Magnesium hydroxide
• Magnesium sulphate
• Magnesium carbonate

How can rusting of iron be prevented?

• Applying a coat of paint or grease
• Exposing iron to oxygen and water
• Heating iron at high temperature
• Mixing iron with copper

What is the new substance formed when copper sulphate reacts with iron?

• Copper sulphate
• Iron sulphate
• Copper
• Iron oxide

What is the process called when a gas changes into a liquid?

• Evaporation
• Condensation
• Melting
• Freezing

What is the product of the chemical reaction between vinegar and baking soda?

• Carbon dioxide
• Oxygen
• Water
• Hydrogen

What is the purpose of crystallisation?

• To prevent rusting
• To produce new substances
• To obtain pure substances from solutions
• To change the physical properties of a substance

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

• Setting of curd
• Cutting a piece of paper
• Melting of ice
• Stretching a rubber band