Natural Sciences Grade 8 June 2020 Memo

Downloaded from hlayiso.com GRADE 8 NATURAL SCIENCES REVISION BOOKLET (2020) QUESTION PAPER A – Page 1 QUESTION PAPER B – Page 9 QUESTION PAPER C – Page 17 MEMORANDUM A – Page 26 MEMORANDUM B – Page 29 MEMORANDUM C – Page 33 CONTENT LIFE AND LIVING (Term 1) MATTER AND MATERIAL (Term 2)

Downloaded from hlayiso.com Natural Sciences Grade 8 1 Revision Booklet Term 1 and 2 REVISION QUESTION PAPER A SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A – D) next to the question number (1.1.1 – 1.1.10). 1.1.1 During the test for starch, a green leaf is placed in boiling alcohol to ... A break the cell walls. B to extract the chlorophyll. C to remove starch. D stop metabolic processes. (1) 1.1.2 Which one of the following is arranged from largest to smallest? A Population, community, ecosystem, biosphere. B Ecosystem, biosphere, community, population. C Biosphere, ecosystem, community, population. D Biosphere, ecosystem, population, community. (1) Questions 1.1.3 and 1.1.4 are based on the diagram of the food chain below. Study it and answer the questions. grass locust frog snake 1.1.3 What do the arrows in the food chain above indicate? A Trophic levels. B Who consumes/eats whom. C Flow of energy. D A common food chain. (1) 1.1.4 In the food chain shown above, which organism is the autotroph? A Snake B Locust C Frog D Grass (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 2 Revision Booklet Term 1 and 2 1.1.5 Which one of the following causes malaria in humans? A Protista. B Fungi. C Bacteria. D Viruses. (1) 1.1.6 What are the horizontal rows on the Periodic Table called? A Groups B Columns C Families D Periods (1) 1.1.7 If an atom has 12 protons in the nucleus, then it must also have ... to be neutral. A 12 protons around the nucleus B 12 neutrons in the nucleus C 12 electrons around the nucleus D 12 electrons in the nucleus (1) 1.1.8 Which of the following is a property of a solid? A It flows. B The particles slide past each other. C It undergoes a phase change. D It has a defined shape. (1) 1.1.9 Melting is the change in state of a… A liquid to a solid. B liquid to a gas. C solid to a gas. D solid to a liquid. (1) 1.1.10 Water is different from other substances because it is … A more dense as a solid than a liquid. B less dense as a solid than a liquid. C more dense as a solid than a gas. D less dense as a solid than a gas. (1) [10]

Downloaded from hlayiso.com Natural Sciences Grade 8 3 Revision Booklet Term 1 and 2 1.2 Give ONE word/term for each of the following statements. Write only the word/term next to the question number. 1.2.1 A sub-atomic particle with a positive charge. (1) 1.2.2 The spontaneous spreading of particles from an area of high concentration to an area of low concentration. (1) 1.2.3 The amount of mass per unit volume. (1) 1.2.4 A substance that cannot be broken down into simpler substances by chemical methods. (1) 1.2.5 Matter that can flow and does not have a specific shape. (1) [5] SECTION A: [15] SECTION B QUESTION 2 2.1 The diagram below illustrates the apparatus used in an experiment. 2.1.1 Identify the experiment illustrated by the diagrams. (1) 2.1.2 Write down a hypothesis for this experiment. (2) 2.1.3 Identify independent variable. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 4 Revision Booklet Term 1 and 2 2.1.4 Identify dependent variable. (1) 2.1.5 Explain what the result of the iodine indicates. (2) [7] QUESTION 3 3.1 The following food web shows the feeding relationships between organisms in a Savannah ecosystem. Answer the questions that follow. 3.1.1 Explain in your own words what an ecosystem is. (2) 3.1.2 Why is it important that an animal adapt to its environment? (1) 3.1.3 How is the leopard adapted to his environment? (2) 3.1.4 In a balanced ecosystem, there are more impala than leopards. Explain why this is so. (2) 3.1.5 Due to veld fires, a large number of the shrubs, trees and grassland are destroyed that forms part of the above-mentioned ecosystem. Explain how this destruction will influence the ecosystem. (2)

Downloaded from hlayiso.com Natural Sciences Grade 8 5 Revision Booklet Term 1 and 2 3.2 The accompanying diagram represents an ecological pyramid of a certain food chain in nature. A B C D 3.2.1 Which LETTER represents the producers? What is the main role of the producers in the food chain? (2) 3.2.2 Why are there usually only a few organisms at the top of an ecological pyramid? (2) 3.2.3 What type of consumer is represented by the letter C? (1) 3.2.4 Which TWO letters represent carnivores? (2) 3.2.5 Which type of organism is not represented in the diagram? (1) [17] SECTION C QUESTION 4 4.1 Use the Periodic Table of elements provided to write down the NAME of an element that: 4.1.1 is a non-metal in Group 1. (1) 4.1.2 is represented by the symbol Na. (1) 4.1.3 has six protons in the nucleus of one atom. (1) 4.1.4 is a noble gas in period 2. (1) 4.1.5 is in Group 2, Period 3. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 6 Revision Booklet Term 1 and 2 4.2 Marius collected some seawater near the beach. The seawater tasted salty and was full of fine sand. He separated the sand from the seawater using the apparatus shown below. 4.2.1 Name the apparatus labelled M. (1) 4.2.2 Name the method used here to separate the sand from the seawater. (1) 4.2.3 Substance L was retained by the filter paper. Give the name of the substance. (1) 4.2.4 Substance N passed through the filter paper. Name one ingredient of substance N. (1) [9] QUESTION 5 5.1 The particle model of matter can be used to represent different substances. A B C

Downloaded from hlayiso.com Natural Sciences Grade 8 7 Revision Booklet Term 1 and 2 5.1.1 Which diagram, A, B or C, represents a diatomic molecule? Give a reason for your answer. (2) 5.1.2 Compare the three phases of matter in terms of the forces between the particles. (3) 5.1.3 How many types of molecules are found in diagram C? (1) 5.1.4 Which diagram represents particles with the highest average kinetic energy? Explain your answer in terms of the particle model of matter. (2) 5.1.5 Why does diffusion not take place in B? (2) 5.2 A learner sets up the apparatus shown below to measure the volume of a steel ball. Study the diagrams and answer the questions that follow. Reading 5.2.1 Give the name of the apparatus, which is used to measure the volume of the steel ball. (1) 5.2.2 When a steel ball is carefully placed into apparatus A, the water level increases to show a new volume as shown in B. Write down the new reading for the volume of the water in apparatus B. (1) 5.2.3 Calculate the volume of the steel ball from the information shown above. Show all your calculations. (2) 5.2.4 Explain why the steel ball drops to the bottom. (1) [15]

Downloaded from hlayiso.com Natural Sciences Grade 8 8 Revision Booklet Term 1 and 2 QUESTION 6 A chemical reaction is represented by the following diagram: oxygen 6.1 Write the name of the product(s) for this reaction. (1) 6.2 Describe in which way the atoms in this reaction are the same before and after the reaction. (2) 6.3 Describe in which way the atoms in this reaction differ before and after the reaction. (2) 6.4 In which phase does the product occur? Give a reason for your answer visible in the diagram. (2) [7] SECTION B AND C: 55 GRAND TOTAL: 70

Downloaded from hlayiso.com Natural Sciences Grade 8 9 Revision Booklet Term 1 and 2 REVISION QUESTION PAPER B SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A – D) next to the question number (1.1.1 – 1.1.10). 1.1.1 The most important source of light and heat on Earth is … A oil. B electricity. C the Sun. D volcanoes. (1) 1.1.2 The products of photosynthesis are … A glucose and oxygen. B carbon dioxide and water. C glucose and carbon dioxide. D carbon dioxide and oxygen. (1) 1.1.3 Ecology is … A a combination of all ecosystems. B the study of the interactions of organisms with each other and their physical and chemical environment. C a community of animals, plants and people. D a group of people that stays in one place that has a specific common characteristic. (1) 1.1.4 The following is an example of a biotic component of an ecosystem. A A clean cement dam that contains only water. B The wind. C Heat. D A grassland. (1) 1.1.5 The following is NOT an example of a micro-organism. A Virus. B Mushroom. C Bacterium. D Protista. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 10 Revision Booklet Term 1 and 2 1.1.6 Atoms consist of … A elements and compounds. B neutrons, electrons and compounds. C protons, electrons and neutrons. D elements, compounds, neutrons, electrons and protons. (1) 1.1.7 The following particles are found in the nucleus of an atom: A Neutrons and electrons. B Neutrons, elements and electrons. C Protons and neutrons D Protons, electrons and neutrons. (1) 1.1.8 The melting point of element X is 25°C. The boiling point of the same element is 70°C. At 30°C the element is a … A solid. B liquid. C gas. D vapour. (1) 1.1.9 In which one of the following substances will the distances between the particles inside the substance be the greatest? All substances shown have the same volume. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 11 Revision Booklet Term 1 and 2 1.1.10 The reactants in a chemical reaction are … A all the substances that appear in the solid phase. B the new substances that are formed. C all the substances that are involved. D all the substances that react with each other. (1) [10] 1.2 Give ONE word/term for each of the following statements. Write down only the word/term next to the question number. 1.2.1 The process whereby energy is released from food through a range of chemical reactions. (1) 1.2.2 The term used for the various stages in the food chain. (1) 1.2.3 Living objects that are too small to view with the naked eye and can only be observed through a microscope. (1) 1.2.4 Positively charged particles in the nucleus of an atom. (1) 1.2.5 The name of the scientific theory that explains that all matter (solids, liquids and gases) consists of particles. (1) [5] TOTAL SECTION A: 15

Downloaded from hlayiso.com Natural Sciences Grade 8 12 Revision Booklet Term 1 and 2 SECTION B QUESTION 2 The following diagram illustrates two life sustaining processes. Answer the questions that follow: 2.1. Describe the process of photosynthesis. (2) 2.2 Write down the word equation for respiration. (2) 2.3 Which process will take place in the following organisms? ONLY write PHOTOSYNTHESIS or RESPIRATION or BOTH. 2.3.1 Animals (1) 2.3.2 Plants (1) 2.4 Explain the relationship between glucose and starch. (1) [7]

Downloaded from hlayiso.com Natural Sciences Grade 8 13 Revision Booklet Term 1 and 2 QUESTION 3 3.1 Explain the difference between producers and consumers in a food web. (2) 3.2 Study the diagram of a food web. Give an example of each of the following from the food web: 3.2.1 A producer (1) 3.2.2 A tertiary consumer (1) 3.2.3 An insectivore (1) 3.2.4 A predator (1) 3.3 Explain the impact on the food web if the hawk is removed from the food web. (3)

Downloaded from hlayiso.com Natural Sciences Grade 8 14 Revision Booklet Term 1 and 2 3.4 Listed below are three types of adaptations:  Structural  Functional  Behavioural Use the list to identify the type of adaptation in each of the following cases: 3.4.1 The jaw of a rabbit is adapted for a herbivore diet. (1) 3.4.2 Coats of mice grow faster and become thicker when they relocate to colder areas. (1) 3.4.3 Hawks have hooked beaks that are designed for tearing off meat. (1) 3.4.4 Mushrooms increase the surface area of the gills under their caps to produce more spores. (1) 3.5 Explain why it is important that organisms can adapt. (2) [15] QUESTION 4 Give an EXAMPLE for each of the following: 4.1 A virus that causes AIDS. (1) 4.2 Food that is produced by using micro-organisms. (1) 4.3 Medicine that is produced by using micro-organisms. (1) 4.4 The name of a scientist that developed a method to remove bacteria by boiling and cooling of liquids. (1) [4] SECTION C QUESTION 5 5.1 Different types of substances are represented in the diagrams below. Answer the questions that follow: Write down the LETTER of the diagram which best represents: 5.1.1 An element that consists of single atoms. (1) 5.1.2 An element that consists of diatomic molecules. (1) 5.1.3 A compound. (1) 5.1.4 A mixture of elements. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 15 Revision Booklet Term 1 and 2 5.2 Consider the three phases of matter illustrated in the diagram below. Describe in detail the arrangement and behaviour of particles in a gas. (4) 5.3 When you walk past a bakery, you can smell the fresh bread that is being baked. This is possible due to the diffusion of gases. 5.3.1 Explain what diffusion is. (2) 5.3.2 How does diffusion that take place in liquids compare to diffusion in gases? (1) 5.3.3 Explain why it is NOT possible for diffusion to take place in solids. (2) [13] QUESTION 6 6.1 When sand and ice are added to a glass of water, the sand sinks to the bottom of the glass while the ice floats on the water as shown below. Ice Water Sand 6.1.1 Write down a definition for density. (2) 6.1.2 Write down the three substances (water, sand and ice) in order of INCREASING density. (3)

Downloaded from hlayiso.com Natural Sciences Grade 8 16 Revision Booklet Term 1 and 2 6.2 Consider the picture of a ship sailing on the sea. 6.2.1 Which one of water and iron has the highest density? (1) 6.2.2 Explain, by referring to density, why a ship can float on water. (2) 6.3 Study the following diagram. An empty paint tin with its lid on, is full of air. When more air is pumped into the tin, the lid pops off at some stage. Explain why the lid pops off when more air is pumped into the tin. (3) [11] QUESTION 7 7.1 Atoms of oxygen, hydrogen and carbon are represented by the following symbols: Oxygen Hydrogen Carbon Use the above symbols to draw the following: 7.1.1 One water molecule (2) 7.1.2 Carbon + oxygen gas  carbon dioxide (3) [5] TOTAL SECTION C: 29 GRAND TOTAL: 70

Downloaded from hlayiso.com Natural Sciences Grade 8 17 Revision Booklet Term 1 and 2 REVISION QUESTION PAPER C SECTION A QUESTION 1 1.1 Four options are given as possible answers to the following questions. Every question has only ONE correct answer. Choose an answer and write down only the letter (A – D) next to the question number (1.1 – 1.10). 1.1.1 What are the five levels of environmental organization from the simplest to the most complicated? A Biosphere, Ecosystem, Community, Population, Organism B Ecosystem, Population, Organism, Community, Biosphere C Biosphere, Community, Population, Organism, Ecosystem D Organism, Population, Community, Ecosystem, Biosphere (1) 1.1.2 The reason for boiling a green leaf in alcohol during the test for starch is to … A break down the cell walls. B extract the chlorophyll. C remove starch. D stop metabolic processes in the leaf. (1) 1.1.3 A certain plant requires moisture, oxygen, carbon dioxide, light and minerals in order to survive. This statement shows that living organisms depend on… A biotic components. B abiotic components. C symbiotic relationships. D carnivore-herbivore relationships. (1) 1.1.4 The following is NOT an example of a micro-organism. A Virus. B Mushroom. C Bacterium. D Protista. (1) 1.1.5 Which one of the following statements is FALSE? A Malaria is caused by bacteria. B Micro-organisms cannot be seen with the naked eye. C An example of a waterborne disease is cholera. D Washing hands and sterilizing can prevent the spread of diseases. (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 18 Revision Booklet Term 1 and 2 1.1.6 Jade wants to test whether the gas produced during an experiment is carbon dioxide gas. Which one of the following reactants can Jade use to test for the presence of carbon dioxide gas? A Copper hydroxide. B Milky white lime water. C Clear lime water. D Iodine solution. (1) 1.1.7 Which one of the following symbols represents hydrogen? A Hg B He C Hy D H (1) 1.1.8 Protons and neutrons are responsible for the ... of an atom. A mass B volume C density D size (1) 1.1.9 Which one of the following is NOT an example of a compound? A H2O B O2 C CuCl2 D CO2 (1) 1.1.10 Sea water is an example of a(n) ... A atom. B compound. C mixture. D element. (1) [10] QUESTION 2 2.1 Give ONE word/term for each of the following descriptions. Write only the correct word/term next to the question number (2.1.1 – 2.1.5) in your ANSWERBOOK. 2.1.1 When all the individuals of a species die out. (1) 2.1.2 A type of food sugar, produced by plants during photosynthesis. (1) 2.1.3 Body covering that makes an animal hard to see. (1) 2.1.4 A live animal that is hunted. (1) 2.1.5 The introduction of a substance which can contribute to an imbalance in an ecosystem. (1) [5]

Downloaded from hlayiso.com Natural Sciences Grade 8 19 Revision Booklet Term 1 and 2 QUESTION 3 3.1 Choose the description in COLUMN B that best matches the item in COLUMN A. Only write down the letter (A - I) next to the correct question number (3.1.1 – 3.1.5) in your ANSWER BOOK, e.g. 3.1.6 J. COLUMN A COLUMN B 3.1.1. Proton A. Compound 3.1.2. Atom B. Negatively charged sub-atomic particle 3.1.3. Electron C. Positively charged sub-atomic particle 3.1.4. Molecule D. Sub-atomic particle that has no charge 3.1.5. Density E. Two or more atoms chemically bonded F. Smallest building block of matter G. Element H Mass per unit volume I Measured in gram per cm2 [5] TOTAL SECTION A: 20

Downloaded from hlayiso.com Natural Sciences Grade 8 20 Revision Booklet Term 1 and 2 SECTION B QUESTION 4 The graph below shows the number of Tuberculosis (TB) patients with known HIV status in South Africa, for the period 2004 to 2006. The diseases mentioned are caused by micro-organisms. Study the graph and answer the questions that follow. 4.1 What was the TOTAL number of patients with Tuberculosis (TB) in the year 2006? (1) 4.2 How many TB patients were diagnosed HIV-positive in 2006? (1) 4.3 Is the prevalence of TB patients that are diagnosed positively with HIV increasing or decreasing? Explain your answer by comparing the data in the graph for the years 2004, 2005 and 2006. (2) 4.4 AIDS and TB are caused by harmful micro-organisms. Identify the type of micro-organism that causes: 4.4.1 AIDS (1) 4.4.2 TB (1) 4.5 Some micro-organisms are classified as useful to human beings. Name TWO ways in which they are used to our advantage. (2) 4.6 Name TWO ways in which the spread of AIDS can be prevented or minimised. (2) [10]

Downloaded from hlayiso.com Natural Sciences Grade 8 21 Revision Booklet Term 1 and 2 QUESTION 5 The diagram below represents important cellular processes that take place in green plants. Complete the table by writing down the number and correct answer. Water + Gas ………. + Gas STATEMENT PROCESS A PROCESS B Name process B. Photosynthesis 5.1 Name the important gases that are needed in 5.2 5.3 each of the processes. Name the gas that is released by each 5.4 5.5 process. Name the main usable product formed by 5.6 5.7 each process. [7]

Downloaded from hlayiso.com Natural Sciences Grade 8 22 Revision Booklet Term 1 and 2 QUESTION 6 Study the diagram below and answer the questions that follow. 6.1 Write down the name of one herbivore that is found in the diagram. (1) 6.2 Write down the name of a decomposer that is found in the diagram. (1) 6.3 Write down a food chain consisting of five different organisms found in the diagram. Do not redraw the pictures. Use the words given in the diagram. (3) 6.4 Are plants or animals the better source of energy for humans? Explain your choice by referring to the trophic levels in which plants and animals are found. (3) [8] QUESTION 7 7.1 Write down the symbol for each of the following elements: 7.1.1 Oxygen (1) 7.1.2 Nitrogen (1) 7.2 Classify each of the following substances (A, B, C and D) as either a mixture, an element or a compound. (4) 7.3. Use the particle model of matter to describe the behaviour of water particles when water is heated and changes from a LIQUID to a GAS. In your answer, refer to the kinetic energy of the particles, the movement of the particles, the open spaces between the particles and the forces that exist between the particles. (4) [10]

Downloaded from hlayiso.com Natural Sciences Grade 8 23 Revision Booklet Term 1 and 2 QUESTION 8 Phakisi and Tristan want to find out what effect an electric current will have on a blue copper chloride solution. Phakisi predicts that an electric current will break up the copper chloride into copper and chlorine. 8.1 Write down an investigative question for the experiment above. (2) 8.2. Define the term electrolysis. (2) 8.3 Describe your observations at the positive electrode (anode). (2) 8.4 Write down the formula for chlorine gas. (1) 8.5 Describe the energy conversion that occurs during the process above. (2) 8.6 Is the blue copper chloride solution an example of an ATOM or a COMPOUND or a MIXTURE? Write down the correct option in your answer book. (1) [10]

Downloaded from hlayiso.com Natural Sciences Grade 8 24 Revision Booklet Term 1 and 2 QUESTION 9 A lady orders a drink in a restaurant. When the waiter brought her drink, she noticed that she could see three different layers of liquids, as shown in the diagram below. Study the diagram and answer the questions that follow. Pomegranate juice Orange juice White grape juice 9.1. Define the term density. (2) 9.2 Will the density of matter increase or decrease when it is heated? Explain your answer by referring to the definition of density. (2) 9.3. Which one of the three layers in the diagram, has the highest density? (1) [5] TOTAL SECTION B: 50 GRAND TOTAL: 70

Downloaded from hlayiso.com Natural Sciences Grade 8 25 Revision Booklet Term 1 and 2 INFORMATION SHEET:

Downloaded from hlayiso.com Natural Sciences Grade 8 26 Revision Booklet Term 1 and 2 MEMORANDUM REVISION PAPER A SECTION A QUESTION 1 1.1.1 B 1.1.2 C 1.1.3 C 1.1.4 D 1.1.5 A 1.1.6 D 1.1.7 C 1.1.8 D 1.1.9 D 1.1.10 B [10] 1.2.1 proton 1.2.2 diffusion 1.2.3 density 1.2.4 element 1.2.5 liquid [5] Section A: [20] AFDELING B VRAAG 2 2.1.1 The experiment to determine if a green leaf will produce starch during photosynthesis. (1) 2.1.2 ‘A green leaf that was exposed to sunlight will contain starch. OR A green leaf that was exposed to sunlight will test positive for starch. (2) 2.1.3 Chlorophyll in the leaf. (1) 2.1.4 Starch is present in the leaf. (1) 2.1.5 The iodine changes from brownish – orange to dark – blue black which indicated that the leaf or other part of the plant contains starch (2) [7]

Downloaded from hlayiso.com Natural Sciences Grade 8 27 Revision Booklet Term 1 and 2 QUESTION 3 3.1.1 An ecosystem consists of the ecological community that includes all living organisms such as plants and animals , together with the non-living environment such as temperature, wind, water, interacting as a system. (2) 3.1.2 The environment change continuously OR and if organisms does not adapt to these changes, they will become extinct (1) 3.1.3 The leopard is camouflaged due to its colouring and spots. This helps it to hide away from its prey so that it can get close to it as possible before chasing. The leopard is adapted to run fast over short periods in order to catch its prey. It has a light streamlined body with strong legs. It has a tail for balance to turn sharp corners while chasing. (any 2 relevant answers) (2) 3.1.4 The impalas are primary consumers and use about 90 % of the energy that they get from the grass, transferring about 10 % to the leopards to consume. There therefore needs to be more impalas than leopards in order to make sure that the leopards are supported in terms of food supply. Also to ensure that the leopards do not eat all the impalas and the impala population does not die out. (2) 3.1.5 If the shrubs and grass are burned all the animals would suffer. There be no food for the primary consumers and they may die out. This would therefore result in all the secondary and tertiary consumers be affected. (2) 3.2.1 D, the producers are organisms that are able to produce their own organic food during photosynthesis. (2) 3.2.2 The organisms in each level use most of the energy (90%) for their own life processes. The consumers at the top of a food pyramid has much less energy available to them and only a few consumers can be supported. (2) 3.2.3 Primary consumers OR herbivores OR omnivores (1) 3.2.4 A and B. (2) 3.2.5 Decomposer(s) (1) [17] Section B : [24] SECTION C QUESTION 4 4.1.1 Hydrogen (1) 4.1.2 Sodium (1) 4.1.3 Carbon (1) 4.1.4 Neon (1) 4.1.5 Magnesium (1)

Downloaded from hlayiso.com Natural Sciences Grade 8 28 Revision Booklet Term 1 and 2 4.2.1 Funnel (1) 4.2.2 Filtration (1) 4.2.3 Filtrate (1) 4.2.4 Water OR salt (1) [9] QUESTION 5 5.1.1 A Consist of 2 atoms.  (2) 5.1.2 The forces between particles of solids are the strongest.Forces between gas particles are very weak, while for liquids the forces between the particles are stronger than those of gases and weaker than those of solids. (3) 5.1.3 Twee Types (1) 5.1.4 ASpaces between particles of gasses is the largest OR the forces of attraction is smaller is the smallest and particles can move freely.  (2) 5.1.5 Particles in solids does not move around, they only vibrate on the spot. so it it not possible for the particles to travel from a place of high density to a place of lower density. (2) 5.2.1 Measuring cylinder (1) 5.2.2 60 cm  (1) 5.2.3 60 – 40 = 20 cm (3) [15] QUESTION 6 6.1 magnesium oxide (1) 6.2 The same amount of atoms before and after the reaction.  (2) 6.3 Before the reaction, all the magnesium atoms were bonded with each other and all the oxygen atoms were bonded with each other.  After the reaction the magnesium atoms have bonded with the oxygen atoms. (2) 6.4 solid phase Particles is close together (attracted to each other) (2) [7] SECTION B and C:[55] TOTAL: [70]

Downloaded from hlayiso.com Natural Sciences Grade 8 29 Revision Booklet Term 1 and 2 MEMORANDUM REVISION PAPER B SECTION A QUESTION 1.1 1.1.1 C 1.1.2 A 1.1.3 B 1.1.4 D 1.1.5 B 1.1.6 C 1.1.7 C 1.1.8 B 1.1.9 C 1.1.10 D [10] QUESTION 1.2 1.2.1 Respiration 1.2.2 Trophic level(s) 1.2.3 Micro-organism(s) 1.2.4 Proton(s) 1.2.5 Particle model of matter [5] TOTAL SECTION A:[15]

Downloaded from hlayiso.com Natural Sciences Grade 8 30 Revision Booklet Term 1 and 2 SECTION B QUESTION 2 2.1 Plants (green / contain chlorophyll) use carbon dioxide (from the air), water (from the soil) and energy from the Sun (in a series of chemical reactions) to produce glucose (food). (2) 2.2 glucose + oxygen  energy + carbon dioxide + water (2) 2.3.1 Respiration (1) 2.3.2 Both (1) 2.4 Plants change glucose into starch. OR Starch is a more complex form of glucose. OR Many glucose molecules form a starch molecule. (1) [7] QUESTION 3 3.1 Producers make their own food. Consumers obtain food from plants, either directly (herbivores) or indirectly (carnivores). (2) 3.2.1 Grass OR Shrubs (1) 3.2.2 Hawk OR Fox (1) 3.2.3 Thrush (1) 3.2.4 Hawk OR Fox OR Weasel (1) 3.3 The prey population will explode. When prey become scarcer, the predator population declines until the prey is again more abundant. Therefore, the two balance each other. OR If the hawk is removed, the number of birds, rabbits, squirrels and mice will increase. This will result in the numbers of caterpillars to reduce as well as the amount of grass and shrubs. If there is no food for the primary consumers they will starve and can die out (become extinct). (3) 3.4.1 Structural (1) 3.4.2 Functional OR Structural (1) 3.4.3 Structural (1) 3.4.4 Functional (1) 3.5 The environment changes continuously and if organisms do not adapt to these changes, they will become extinct. (2) [15]

Downloaded from hlayiso.com Natural Sciences Grade 8 31 Revision Booklet Term 1 and 2 QUESTION 4 4.1 HIV OR HI-virus OR Human Immunodeficiency Virus (1) 4.2 yoghurt / cheese / bread / beer (1) 4.3 penicillin (1) 4.4 Louis Pasteur (1) [4] TOTAL SECTION B:[26] SECTION C QUESTION 5 5.1.1 C (1) 5.1.2 A (1) 5.1.3 D (1) 5.1.4. E (1) 5.2 In a gas, the particles...  have no particular arrangement.  move very fast.  have extremely weak forces between them.  have very big spaces between them compared to solids and liquids. (4) 5.3.1 Diffusion is a process in which particles in liquids and gases move (separate and spread) from a highly-concentrated area to an area with a lower concentration of those particles. (2) 5.3.2 Diffusion in liquids occurs slower than diffusion in gases. OR Diffusion in gases occurs faster than diffusion in liquids. (1) 5.3.3 Particles in solids do not move around, they only vibrate on the spot. Thus it is not possible for the particles to travel from a place of high density to a place of lower density. (2) [13]

Downloaded from hlayiso.com Natural Sciences Grade 8 32 Revision Booklet Term 1 and 2 QUESTION 6 6.1.1 The density of a material describes the amount of mass in a given volume of that material. (2) 6.1.2 ice water sand ( MUST be this order) (3) 6.2.1 Iron (1) 6.2.2 The ship is filled with air. The (average) density of the ship is lower than the density of the water and can float on the water. (2) 6.3 More air particles are pumped into the tin which causes more collisions with the lid and the sides of the tin. That will increase the pressure inside the tin and the lid will pop off. (3) [11] QUESTION 7 7.1.1 One oxygen atom Two hydrogen atoms (2) 7.1.2 +  (3) [5] SECTION C:[29] GRAND TOTAL: [70]

Downloaded from hlayiso.com Natural Sciences Grade 8 33 Revision Booklet Term 1 and 2 MEMORANDUM REVISION PAPER C SECTION A QUESTION 1 1.1.1 D 1.1.2 B 1.1.3 B 1.1.4 B 1.1.5 A 1.1.6 C 1.1.7 D 1.1.8 A 1.1.9 B 1.1.10 C [10] QUESTION 2 2.2.1 Extinction 2.2.2 Glucose 2.2.3 Camouflage 2.2.4 Prey 2.2.5 Pollution [5] QUESTION 3 3.1.1 C 3.1.2 F 3.1.3 B 3.1.4 E 3.1.5 H [5] TOTAL SECTION A: 20

Downloaded from hlayiso.com Natural Sciences Grade 8 34 Revision Booklet Term 1 and 2 SECTION B QUESTION 4 4.1 750 000 + 250 000 = 1000 000 (1) 4.2 250 000 (1) 4.3 An overall increase of TB patients that were diagnosed with HIV can be observed, but the increase is slowing down. 2004  2005 increase was 100 000 patients, while in the period 2005  2006 the increase was 50 000 patients. (2) 4.4.1 AIDS - Virus (1) 4.4.2 TB - Bacteria (1) 4.5 Decomposers are useful micro-organisms that play an important role in the ecosystem as they break down dead plant and animal matter. People use micro-organisms in the fermentation process when producing dairy products (yoghurt, cheese), brewing beer, making wine or baking bread. Some micro-organisms are used for making medicine, like penicillin. (Any two advantages) (2) 4.6 Use condoms during sexual intercourse. Do not share needles. If you are HIV-infected and pregnant, talk to your health care provider about taking ARV's. Protect cuts, open sores, and your eyes and mouth from contact with blood. (Any two preventions) (2) [10] QUESTION 5 5.1 respiration 5.2 carbon dioxide 5.3 oxygen 5.4 oxygen 5.5 carbon dioxide 5.6 glucose 5.7 energy [7]

Downloaded from hlayiso.com Natural Sciences Grade 8 35 Revision Booklet Term 1 and 2 QUESTION 6 6.1 locust (1) 6.2 mushrooms (1) 6.3 grass → locust → small bird → eagle → mushroom Grass first Mushroom last All the others in the correct order. (3) 6.4 Plants/grass. Plants are in a lower trophic level than animals. Energy comes directly from the sun and is absorbed by plants. This energy is then consumed by animals and the biggest part of the energy is used for life processes. Therefore, if you consume animals, you will get access to less energy than if you consume the same amount of plants. (3) [8] QUESTION 7 7.1.1 O (Accept: O2) (1) 7.1.2 N (Accept: N2) (1) 7.2 A – Compound B – Mixture C – Element D - Compound (4) 7.3 The kinetic energy of water particles increases when heated. The particles move faster and travel over larger distances. The open spaces between water particles increase and the forces between water particles become weaker / less effective when water changes phase from a liquid to a gas. (4) [10]

Downloaded from hlayiso.com Natural Sciences Grade 8 36 Revision Booklet Term 1 and 2 QUESTION 8 8.1 What effect will an electric current have on a copper chloride solution? (2) 8.2 Electrolysis is the decomposition (breaking down) of a compound into elements by using an electric current. (2) 8.3 Gas/Cl2/Chlorine bubbles are formed/liberated. OR Chorine gas can be smelled. OR Yellow-green gas be seen. (2) 8.4 Cl2 or Cℓ2 (Do not accept Cl) (1) 8.5 Electric energy is converted to chemical energy. (2) 8.6 Mixture. (1) [10] QUESTION 9 9.1 Density is defined as the mass per unit volume of a substance. OR Density is the amount of mass in a given volume. (2) 9.2 Decrease. When heated, the volume of the substance will increase while the mass remains the same. Because Density = mass / volume, the density will decrease. (2) 9.3 White grape juice. (1) [5] TOTAL SECTION B: 50 GRAND TOTAL: 70