The diagram shows a glass container with water and cooking oil. Identify Q and R, suggest a separation method, and explain why Q is on top of R.

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9. The diagram below shows a glass container into which water and cooking oil were poured. The two liquids settled as shown. Study and use it to answer the questions that follow.

• a) Which of the two liquids is represented by:
  • (i) Q: Cooking oil
  • (ii) R: Water
• b) State any one method that can be used to separate the two liquids.
  • Decantation (or using a separating funnel).
• c) Why has liquid Q settled on top of liquid R?
  • Liquid Q (cooking oil) is less dense than liquid R (water), causing it to float on top.

10. State any two machines that can be used to measure mass.

• (i) Beam balance
• (ii) Electronic balance

11. (a) What is the meaning of the term sinking?

• Sinking is the process where an object moves downwards through a liquid because its density is greater than the density of the liquid.

• b) Give any two examples of sinking objects.

  • (i) Stone
  • (ii) Metal nail

• c) Why do some objects sink in water?

  • Some objects sink in water because their density is greater than the density of water.

12. Moses wanted to find the volume of an irregular object. He had the following materials for the experiment; an irregular object, thread, overflow can and water.

• a) Name one material Moses forgot to include on the list of his materials.
  • Measuring cylinder (or beaker).
• b) What is the use of the thread in the experiment?
  • The thread is used to gently lower the irregular object into the water without splashing and to ensure it is fully submerged.
• c) Describe how Moses will get the volume of the irregular object in this experiment.