The City School PAF Chapter

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1 The City School PAF Chapter Comprehensive Worksheet May 2016 Science Class 7 Candidate Name: Index Number: Section: Branch/Campus: Date: INSTRUCTIONS: Write your name, index number, section, branch/campus and date clearly in the space provided. Read and follow the instructions of the given questions. Answer all the questions in the space provided. Select only one answer when made to choose, otherwise no marks will be given. Check your answers before handing your paper in. Marks for each section are shown below. This paper consists of 09 printed pages including the cover page. For Examiner s use only Sections Section A Section B Total Question Max. Marks Marks Obtained Percentage Grade INVIGILATED BY MARKED BY MARKS TALLIED BY The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 1 of 9

2 OBJECTIV [ /50] Q.1 Encircle the best answer from the given options. [ /30] 1.Size of an animal cell is Same as size of a plant cell Smaller than plant cell Bigger than plant cell 2.The thread like structure present in the nucleus cytoplasm chromosomes chloroplast 3.They are made up of proteins called DNA Chloroplast Genes Genes and chromosomes 4.The characteristics of an organism are passed down from one generation to the next by genes chromosome nucleus 5.Function of nucleus is Cell repair Control all functions of cell Both of the above 6.These substances can change from solid to vapours form directly without melting Iodine Dry ice Ammonium chloride All of the above 7.The particles in a solid can Not move Vibrate on their fixed positions Move constantly and randomly 8.Physical change can bring about the change in The nature of a substance The state of a substance Both of the above 9.Diffusion is the movement of particles from an area of Higher concentration to lower concentration lower concentration to higher concentration 10. This gas is poisonous and brown in colour nitrogen carbon dioxide Bromine The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 2 of 9

3 11. A chemical formula shows The NO. of atoms in a molecule The NO. of atoms in an element The NO. of atoms in a compound The NO. and kinds of atoms in a molecule 12. Which of the following substances consist of two different kinds of atoms chemically combined together? Fe KOH KCl 13. Molecules of an element are made up of 2 atoms of the same element and 2 atoms of another element atoms of the same element atoms of 2 different elements 14. Which of the following instruments can be used to look at atoms? binoculars compound microscope electron microscope 15. These are pure substances mixtures elements and compounds only elements 16. Scientific word used for burning is combustion compatible combustible 17. When Magnesium burns in air, it forms a white solid called Magnesium carbonate Magnesium oxide Magnesium hydroxide 18. Natural gas, a fossil fuel is made up mostly of the compound called Carbon dioxide methane metal 19. A chemical reaction in which a substance breaks down into two or more simple substances is called decomposition combination combustion 20. Formation of ice from water is due to Cooling Freezing Melting The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 3 of 9

4 21. Substances that burn and release energy are called fuels fossil fuels fossils 22. When the air holes of a Bunsen burner are closed it gives out Luminous flame Non- luminous flame No flame at all 23. Crude oil extracted from the ground is a sticky black liquid, different substances are separated from it by a process called decomposition distillation fractional distillation 24. The 3 R S means Read, write, reduce Reduce, reuse, recycle Road, rail, roam 25. To use energy and avoid wasting it is called Conversion of energy Conservation of energy Diversion of energy 26. In an electrical motor electrical energy is converted into Heat and light energy Sound and light energy Sound and mechanical energy 27. In an electrical bulb, electrical energy is converted into Heat and light energy light and mechanical energy 28. when a battery is used up and goes flat what is used up? Is it energy voltage current mass 29. in a parallel circuit when more resistors are added, its resistance decreases increases remains the same 30. in a closed circuit electrical current flows from negative to positive terminal positive to negative terminal none of the terminal The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 4 of 9

5 Q.2 Fill in the blanks with suitable answers. [ /5] 1. Chemical change is a change. 2. Sublimation is an example of change. 3. The process of breaking down a substance into simpler substances by heat is called decomposition. 4. When a dilute acid reacts with a metal, gas is produced and when dilute acid reacts with carbonates gas is produced. 5. During a chemical reaction, no mass is gained or lost, mass is Q.3 State true or false. Write correct statement for a false one. [ /10] 1. The cell wall is semi permeable membrane. 2. In both animal and plant cells, cell division starts from the centre of the nucleus. 3. Democritus observed that some pollen grains were moving randomly and constantly in water. 4. Gas particles vibrate on their fixed positions. 5. When an atom gains or loses protons it becomes an ion. 6. The gases which exist in atomic state are called as nitrates. 7. Biomass is an example of non- renewable energy resource. 8. Coal was formed underground when plankton died and got buried underground. 9. A motor is used to open or close a circuit. 10. The current flowing through each component in a series circuit is different every where. The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 5 of 9

6 Q.4 Give scientific reasons [ /5] 1. Plant cells can make their own food. 2. Solids cannot flow. 3. A chlorine atom has 17 electrons in it, while a chloride ion has 18 electrons in it. 4. When we burn fossil fuels they cause air pollution. 5. An electrical circuit does not work when the switch is open. The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 6 of 9

7 SUBJECTIVE: 50 MARKS Q.1 (a) - Differentiate between an animal cell and a plant cell. [ /4] Part of cell Animal cell Plant cell Size of cell cytoplasm vacuole Shape of cell (b) Complete the table. [ /4] Part of a microscope stage mirror Stage clips Its function Objective lens Q.2 (a) Define the following terms. [ /5] Diffusion: Brownian motion: Sublimation: Density: The particle model of matter: The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 7 of 9

8 (b) Choose the name of the scientist from the box given below and write with his work. [ /5] Democritus Aristotle John Dalton Robert Brown Albert Einstein Scientist His work in the development of Particle Model of Matter. Observed some pollen grains suspended in water were constantly moving about randomly in all directions Suggested that matter is made up of small discrete particles which are like little solid balls Explained that the dead pollen grains were moving because they were being bombarded by the moving water particles Hypothesized that matter is made up of tiny discrete particles called atoms which are too small to be seen Hypothesized that matter has a continuous composition that can be broken down into smaller and smaller pieces Q.3 (a) Name the fossil fuels.why are they called as non- renewable resources of energy? [ /3] (b) Why is the Sun, the main source of almost all the energy resources on the earth? [ /3] (c) Describe Geo thermal energy. [ /2] Q.4 (a) Differentiate between: [ /4] Atom Ion Molecule of element Molecule of compound The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 8 of 9

9 (b) For the following elements, write down the symbols of their atoms and ions. [ /4] Name of the element symbol of its atom symbol of its ion Sodium Aluminium Chlorine calcium Q.5 (a) Differentiate and give examples. [ /4] Physical change Chemical change (b) Chemical reactions are of different types. Write one word equation for each of the following types of chemical reaction. [ /3] i) Combination reaction: ii) Decomposition reaction: iii) Combustion reaction; (c) Which gas is given off when Methane burns in air? [ /1] Q.6 (a) Sarah went out in darkness, she tried to switch on her torch but it did not work. Write the possible faults in her torch, which stopped it from working. [ /4] _ (b) Draw a series circuit and a parallel circuit using symbols. [ /4] Series circuit Parallel circuit The City School/ PAF Chapter/ Comprehensive Worksheet/ May 2016/ Science/ Class 7 Page 9 of 9