What happens when two unlike poles of two different magnets come closer to each other? (1 mark)

Here are the answers to your questions:

16. What happens when two unlike poles of different magnets come closer to each other?

• When two unlike poles of different magnets come closer to each other, they attract each other.
• Answer: They attract each other.

17. State any one advantage of using renewable energy.

• One advantage of using renewable energy is that it does not produce greenhouse gases, thus reducing air pollution and climate change.
• Answer: It does not produce greenhouse gases.

18. What energy change takes place when a piece of wood is burned?

• When wood is burned, chemical energy stored in the wood is converted into heat energy and light energy.
• Answer: Chemical energy is converted into heat and light energy.

19. Read the statement and answer the questions that follow: At $100^\circ C$ and at standard pressure, water changes state from liquid to gas (water vapour). At $0^\circ C$ and below this temperature, liquid water becomes solid water called ice.

• a) What is the boiling point of water?
  • The boiling point of water is the temperature at which it changes from liquid to gas.
  • Answer: 100^\circ C
• b) Determine the melting point of ice.
  • The melting point of ice is the temperature at which solid water (ice) changes back to liquid water, which is the same as the freezing point of water.
  • Answer: 0^\circ C
• c) Name the change of phase from liquid water to ice.
  • The change of phase from liquid water to ice is called freezing or solidification.
  • Answer: Freezing

20. Draw a simple leaf and show the following parts: (Tip: margin, midrib, leaf veins and lamina)

• As an AI, I cannot draw. However, I can describe the parts:
  • Lamina: The broad, flat part of the leaf.
  • Midrib: The central vein running through the lamina.
  • Leaf veins: Smaller veins branching out from the midrib.
  • Margin: The edge of the leaf.

21. Air is a mixture of gases. Give any two examples of gases found in air.

• (i) Nitrogen
• (ii) Oxygen
• Answer: Nitrogen, Oxygen

22. Why is the heart separated into two parts or sections?

• The heart is separated into two parts (right and left) to prevent the mixing of oxygenated blood (from the lungs) and deoxygenated blood (from the body), ensuring efficient oxygen delivery.
• Answer: To prevent mixing of oxygenated and deoxygenated blood.

23. Which of the following organs is not involved in breathing? a. Diaphragm b. Bronchioles c. Oesophagus d. Wind pipe

• The oesophagus is part of the digestive system, not the respiratory system.
• Answer: c. Oesophagus

24. Give any four characteristics of living things.

• (i) Movement
• (ii) Respiration
• (iii) Growth
• (iv) Reproduction
• Answer: Movement, Respiration, Growth, Reproduction

25. Give examples of each of the following bones:

• a) Long bones:
  • Examples include the femur (thigh bone) and humerus (upper arm bone).
  • Answer: Femur, Humerus
• b) Short bones:
  • Examples include the carpals (wrist bones) and tarsals (ankle bones).
  • Answer: Carpals, Tarsals
• c) Flat bones:
  • Examples include the scapula (shoulder blade) and cranial bones (skull bones).
  • Answer: Scapula, Cranial bones

26. Choose the by-products of respiration in human.

(i) carbon dioxide

(ii) oxygen

(iii) water vapour

(iv) nitrogen

• During respiration, humans take in oxygen and release carbon dioxide and water vapour as by-products.
• Answer: (i) carbon dioxide and (iii) water vapour

27. Apart from movement, give any two other functions of the human skeleton.

• (i) Support: The skeleton provides a framework that supports the body.
• (ii) Protection: It protects vital internal organs (e.g., skull protects the brain, rib cage protects the heart and lungs).
• Answer: Support, Protection

28. Where in the digestive system do the following take place?

• This question is incomplete as the specific processes or substances to be located in the digestive system are not provided.