(a) (i) Name the two elements that combine to form water.
(ii) Write a balanced chemical equation to show how the water is formed from the named elements
(b) State two ways of maintaining a balance in an ecosystem.
(c) (i) What is a fertile soil?
(ii) State two factors that cause loss of soil fertility.
(d) Classify the following items as magnetic or non-magnetic substance:
wood, steel blade, rubber and glass jar.
3. (a) (i) What is germination of seed?
(ii) State two conditions necessary for the germination of seed.
(b) State four methods used in identifying farm animals
(c) Explain why it is easier to cut a piece of yam with a sharp knife than with a blunt knife
(d) State three differences between a metal and a non-metal.
4. (a) (i) What is debeaking?
(ii) Give two reasons why debeaking in poultry birds is important.
(b) (i) A steel needle carefully placed on the surface of water floats. What type of force made the steel needle to float?
(ii) Name three substances that could be added to the water to make the steel needle to sink.
(c) (i) Explain why gold is preferred to iron in the making of jewelleries.
(ii) State one way of preventing rusting.
(d) (i) State two elements of climate
(ii) Name the equipment used to measure each of the elements stated in (i) above.
5. (a) (i) What is refraction of light?
(ii) Sketch a diagram to show the path of a light ray when it travels from air to glass.
(b) Explain why it is difficult to separate iron and sulphur mixture after strong heating.
(c) (i) Give two example of digestive enzymes produced in humans.
(ii) For each of the enzymes given in (i), name the part of the human body where the enzyme is produced.
(d) List four methods of applying fertilizers to crops.
6. (a) Consider the substance listed below:
carbon dioxide, gold, bronze, iron, oxygen and ink
From the list, select the substance that:
(i) supports burning
(ii) is used as jewellery;
(iii) is used for making statues
(b) (i) Name two diseases associated with the circulatory system of humans.
(ii) State one way of preventing each of the diseases named in (i)
(c) Give two examples of each of:
(i) major plant nutrients;
(ii) minor plant nutrients.
(d) (i) State two properties of a good thermometric liquid.
(ii) Give two examples of a good thermometric liquid
(a)
(i) The two elements that combine to form water are hydrogen and oxygen.
(ii) Balanced chemical equation: 2H₂ + O₂ → 2H₂O
(b) Two ways of maintaining a balance in an ecosystem:
- Biodiversity conservation
- Sustainable resource management
(c)
(i) Fertile soil is soil that is rich in nutrients and able to support plant growth.
(ii) Factors that cause loss of soil fertility:
- Erosion
- Overuse of chemical fertilizers
(d)
- Magnetic substance: steel blade
- Non-magnetic substances: wood, rubber, glass jar
3.
(a)
(i) Germination of seed is the process by which a seed sprouts and begins to grow into a new plant.
(ii) Conditions necessary for germination of seed:
- Water
- Suitable temperature
(b) Methods used in identifying farm animals:
- Ear tagging
- Microchipping
- Branding
- DNA profiling
(c) It is easier to cut a piece of yam with a sharp knife than with a blunt knife because a sharp knife has a thinner edge that can easily slice through the yam, while a blunt knife has a dull edge that requires more force.
(d)
- Differences between metal and non-metal:
- Metals are good conductors of heat and electricity, while non-metals are poor conductors.
- Metals tend to be shiny and malleable, while non-metals are dull and brittle.
4.
(a)
(i) Debeaking is the process of removing part of a bird's beak.
(ii) Reasons why debeaking in poultry birds is important:
- Prevents feather pecking and cannibalism
- Reduces injuries and infections
(b)
(i) The force that makes the steel needle float is surface tension.
(ii) Substances that could be added to water to make the steel needle sink:
- Soap
- Salt
- Oil
(c)
(i) Gold is preferred to iron in the making of jewelry because gold is highly resistant to tarnish, corrosion, and rust.
(ii) One way of preventing rusting is by applying a protective coating like paint or oil.
(d)
(i) Elements of climate: temperature, precipitation
(ii) Equipment used to measure each element: thermometer, rain gauge
5.
(a)
(i) Refraction of light is the bending of light as it passes from one medium to another.
(ii) Diagram: [Not provided]
(b) It is difficult to separate an iron-sulfur mixture after strong heating because the two substances form a compound (iron sulfide) that cannot be easily separated by physical means.
(c)
(i) Examples of digestive enzymes produced in humans:
- Amylase
- Lipase
(ii) Parts of the human body where the enzymes are produced:
- Amylase is produced in the salivary glands and pancreas
- Lipase is produced in the pancreas
(d) Methods of applying fertilizers to crops:
- Broadcasting
- Foliar feeding
- Fertigation
- Side-dressing
6.
(a)
(i) Oxygen supports burning
(ii) Gold is used as jewelry
(iii) Bronze is used for making statues
(b)
(i) Diseases associated with the circulatory system: heart disease, hypertension
(ii) Ways of preventing the diseases: healthy diet, regular exercise
(c)
(i) Major plant nutrients: nitrogen, phosphorus
(ii) Minor plant nutrients: zinc, magnesium
(d)
(i) Properties of a good thermometric liquid:
- Wide range of temperature measurement
- High thermal conductivity
(ii) Examples of a good thermometric liquid: mercury, alcohol