202110725-PERFORM-STUDENT-WORKBOOK-SCIENCE-G07-FY_Optimized

practice workbook science Grade 7 Name: Roll No: Section: School Name:

by classklap IMAX is India’s only customised content and educational assessment m. 610+ Published Books Team of IITians & PhDs IMAX Program has authored about 610+ Content development and automation are publications which are used by more than led by a team of IITians, data scientists and 4,50,000+ students. education experts Workshops Lakh Assessments IMAX Program has conducted IMAX Program has conducted more than teacher training workshops for more 85,00,000+ assessments across 17 states in the last 10 years. than 15,000+ teachers. Copyright © 2020 BGM Policy Innovations Pvt Ltd) All rights reserved. No part of this publication, including but not limited to, the content, the presentation layout, session plans, themes, key type of sums, mind maps and illustrations, may be reproduced, stored in a retrieval system or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), without the prior, written permission of the copyright owner of this book. This book is meant for educational and learning purposes. The author(s) of the book has/ have taken all reasonable care to ensure that the contents of the book do not violate any copyright or other intellectual property rights of any person in any manner whatsoever. In the event the author(s) has/have been unable to track any source and if any copyright has been inadvertently infringed, please notify the publisher in writing for any corrective action. Some of the images used in the books have been taken from the following sources www.freepik.com, www.vecteezy.com, www.clipartpanda.com Creative Commons Attribution This book is part of a package of books and is not meant to be sold separately. For MRP, please refer to the package price.

This practice book is designed to support you in your journey of learning Science for Class 7. The contents and topics of this book are entirely in alignment with the NCERT syllabus. For each chapter, a concept map, expected objectives and practice sheets are made available. Questions in practice sheets address different skill buckets and different question types, practicing these sheets will help you gain mastery over the lesson. The practice sheets can be solved with the teacher’s assistance. There is a self-evaluation sheet at the end of every lesson, this will help you in assessing your learning gap.



TABLE OF CONTENT • Assessment Pattern: 40 Marks • Assessment Pattern: 80 Marks • Syllabus & Timeline for Assessment • Guided Writing Page 1: 1. Nutrition in Plants Page 8: 2. Nutrition in Animals Page 15: 3. Fibre to Fabric Page 23: 4. Heat Page 32: 5. Acids, Bases and Salts Page 39: 6. Physical and Chemical Changes Page 48: 7. Weather, Climate and Adaptations of Plants and Animals to Climate Page 55: 8. Winds, Storms and Cyclones Page 65: 9. Soil Page 74: 10. Respiration in Organisms Page 82: 11. Transportation in Animals and Plants Page 90: 12. Reproduction in Plants Page 98: 13. Motion and Time Page 112: 14. Electric Current and its Effects Page 120: 15. Light Page 127: 16. Water: A Precious Resource Page 136: 17. Forests : Our Life Line Page 144: 18. Wastewater Story







ASSESSMENT PATTERN Marks: 40 Marks: 40 ASSESSMENT PATTERN Grade 7 / Science Max Internal PAPER: BEGINNER PAPER: PROFICIENT Mark Option Q.No Skill Level Difficulty Level Skill Level Difficulty Level Easy Medium Difficult Easy Medium Difficult Section A (Question Type: VSA) 11 Remembering • Remembering • 21 Remembering • Remembering • 31 Remembering • Remembering • 41 Understanding • Understanding • 51 Understanding • Understanding • 61 Remembering • Remembering • 7 1 • Remembering • Remembering • 81 Remembering • Remembering • 91 Understanding • Understanding • 10 1 • Understanding • Understanding • Section B (Question Type: SA) 11 3 • Remembering • Remembering • 12 3 Understanding • Understanding • Section C (Question Type: LA) 13 5 • Remembering • Remembering • 14 5 • Understanding • Understanding • 15 5 Understanding • Understanding • Section D (Question Type: LA) 16 3 Applying • Applying • 17 3 • Analysing • Analysing • 18 3 Analysing • Analysing • Beginner Paper: (Easy: 50%, Medium: 40%, Difficult: 10%) Proficient Paper: (Easy: 40%, Medium: 40%, Difficult: 20%) Easy Question: Remembering questions directly from the text or from the given exercises. (Mostly from content of book or end of chapter exercise). Medium Difficulty Question: In-depth understanding of questions, not necessarily from the text. (Slightly modified concepts or end of chapter questions). Difficult Question: Question involving creativity like story writing, analysis question like character analysis, justification of title or extracts (mostly requires creative and thinking skills).

ASSAESSSSEMSSEMNETNPTAPTATTETRENRN Marks: 80 Marks: 80 Grade 7 / Science Max Internal PAPER: BEGINNER PAPER: PROFICIENT Mark Option Q.No Skill Level Difficulty Level Skill Level Difficulty Level Easy Medium Difficult Easy Medium Difficult Section A (Question Type: VSA) 11 Remembering • Remembering • 21 Remembering • Remembering • 31 Remembering • Remembering • 41 Remembering • Remembering • 51 Remembering • Remembering • 61 Understanding • Understanding • 71 Understanding • Understanding • 81 Understanding • Understanding • 91 Understanding • Understanding • 10 1 Understanding • Understanding • 11 1 • Remembering • Remembering • 12 1 Remembering • Remembering • 13 1 Remembering • Remembering • 14 1 Understanding • Understanding • 15 1 Understanding • Understanding • 16 1 Applying • Applying • 17 1 • Applying • Applying • 18 1 Applying • Applying • 19 1 • Applying • Applying • 20 1 Applying • Applying • Section B (Question Type: SA) 21 3 Remembering • Remembering • 22 3 Remembering • Remembering • 23 3 Understanding • Understanding • 24 3 • Understanding • Understanding • Section C (Question Type: LA) 25 5 Remembering • Remembering • 26 5 • Remembering • Remembering • 27 5 Understanding • Understanding • 28 5 • Remembering • Remembering • 29 5 Remembering • Remembering • 30 5 • Understanding • Understanding • Section D (Question Type: SA) 31 3 • Applying • Applying • 32 3 Applying • Applying • 33 3 • Analysing • Analysing • 34 3 Analysing • Analysing • 35 3 • Analysing • Analysing • 36 3 Analysing • Analysing •

SYLLABUS FOR ASSESSMENT CHAPTERS PT-1 TE-1 PT-2 TE-2 1. Nutrition in Plants ✓ ✓ ✓ 2. Nutrition in Animals ✓ ✓ ✓ 3. Fibre to Fabric ✓ ✓ ✓ ✓ 4. Heat ✓ ✓ 5. Acids, Bases and Salts ✓ ✓ ✓ 6. Physical and Chemical Changes ✓ ✓ ✓ 7. Weather, Climate and Adaptations of Plants and Animals to Climate ✓ ✓ 8. Winds, Storms and Cyclones ✓ ✓ 9. Soil ✓ 10. Respiration in Organisms ✓ ✓ 11. Transportation in Animals and Plants ✓ 12. Reproduction in Plants ✓ ✓ 13. Motion and Time 14. Electric Current and its Effects 15. Light 16. Water: A Precious Resource 17. Forests : Our Life Line 18. Wastewater Story Assessment Timeline Periodic Test - 1 22nd July to 12th August Term Exam - 1 23rd September to 21st October Periodic Test - 2 16th December to 13th January Term Exam - 1 1st March to 30th March



1. Nutrition in Plants • Explain different modes of heterotrophic Learning Outcome nutrition. By the end of this chapter, you will be: • Cite examples for autotrophs and heterotrophs • Classify plants as autotrophs and heterotrophs in plants. based on their nutrition. • Differentiate an autotroph from a heterotroph. • Explain photosynthesis in plants. Concept Map NUTRITION IN PLANTS AUTOTROPHIC HETEROTROPHIC Prepares food Saptrophytes Parasites Insectivorous Symbionts through photosynthesis Keypoints • Saprophytes depend on dead and decaying matter for their food. Example: Bacteria and fungi • Living organisms obtain energy from the food they eat. • Insectivorous plants trap insects to meet their ni- trogen demands. Example: Pitcher plant. • Based on the mode of obtaining food, organisms are classified into two major groups- Autotrophs • Symbionts: Organisms live together, helping each and Heterotrophs. other to obtain food. Example: Lichen-a symbiotic relationship between an algae and a fungus. • Autotrophs can prepare their own food either by photosynthesis or chemosynthesis. Keywords: Autotrophic, chlorophyll, heterotrophic, host, insectivorous, nutrients, • Oxygen is released and carbon dioxide is taken up nutrition, parasite, photosynthesis, saprotrophs, by plants during photosynthesis. saprotrophic, stomata. • Heterotrophs depend on autotrophs directly or in- directly for food. • Parasites depend on other organisms for their food requirements. Example: Cuscuta 1

1. Nutrition in Plants Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO Prepares food through photosynthesis PS-1 • Saprotrophs Autotrophic • Parasites PS-2 Demonstration of Heterotrophic • Insectivorous photosynthesis • Symbionts PS-3 Study of different modes of nutrition PS-4 in plants Worksheet for “Nutrition in Plants” PS-5 plant showing lid Evaluation with self- and pitcher check or Peer check* Self-evaluation Sheet 2

PRACTICE SHEET - 1 (PS-1) I. Say True Or False: 1. In parasitic nutrition, both the organisms are benefitted. 2. Plants that do not contain chlorophyll will not be able to carry out photosynthesis. 3. Insectivorous plants are photosynthetic plants. 4. Mushroom is a parasite. 5. In a symbiotic relationship, both the organisms benefit from each other. II. Fill in the blanks: 1. The _________ hair absorbs water and minerals from the soil. 2. Carbon dioxide enters the leaf through _______________. 3. Cuscuta is an example of a ______________ plant. 4. ____________ is an insectivorous plant. III. Match the following: COLUMN A COLUMN B ANSWER 1. Autotrophs Water 2. Stomata Photosynthesis 3. Xylem Carbon dioxide 4. Chlorophyll Symbiosis 5. Lichens Mango tree PRACTICE SHEET - 2 (PS-2) I. Give two examples for each of the following: 1. Parasitic plants: 2. Saprophytes: 3. Autotrophs: 4. Insectivorous plants: 5. Organisms that make up lichen: II. Write one word for the following: 1. Plants that depend on other organisms for food. 2. Plants that trap insects for their nitrogen requirement. 3. A relationship between two organisms where one is benefitted while the other is harmed. 4. A relationship between the organisms where both the organisms are mutually benefitted. 5. A process by which the solar energy is converted to chemical energy by plants using chlorophyll. III. Spot as many organisms as possible in the puzzle given by encircling them. Write the names and categorize them into autotrophs and heterotrophs. Classify the heterotrophs into herbivores, carnivores, omnivores and saprophytes. B R O S E A T C R OW AAGNBH I ND I B NBNG I NGERC L Y B A NH B E C OWF A I MU S HROOMF N T G B E R MW F I O E L EPHANTSCX TSAE YNPHBEE CARROTUL S I X 3

PRACTICE SHEET - 3 (PS-3) 8. In the absence of which of the following, will photosynthesis not occur in leaves? I. Choose the correct option: a. Guard cells 1. Which of the following is/are needed for b. Chlorophyll photosynthesis? c. Vacuole a. Chlorophyll d. Space between cells b. Sunlight and water c. Carbon dioxide 9. Which of the following statements is/are d. All of these correct? 2. Which of the following is an insectivorous i. All green plants can prepare their own food. plant? ii. Most animals are autotrophs. a. Cuscuta iii. Carbon dioxide is not required for b. Mushroom photosynthesis. c. Pitcher plant iv. Oxygen is liberated during photosynthesis. d. Mistle toe 3. Plants obtain carbon dioxide from the Choose the correct answer from the options atmosphere through below: a. Leaf b. Stomata (a) (i) and (iv) (b) (ii) only c. Stem (c) (ii) and (iii) (d) (i) and (ii) d. Chloroplast 4. Food is stored in plants as 10. Pitcher plant traps insects because it a. Glucose a. is a heterotroph. b. Starch b. grows in soils which lack in nitrogen. c. Sugar c. does not have chlorophyll. d. Proteins d. has a digestive system like human beings. 5. Pea plants form a symbiotic association with a/an 11. The term that is used for the mode of a. Fungus nutrition in yeast, mushroom and bread- b. Algae mould is c. Virus a. autotrophic d. Bacteria b. insectivorous 6. Ashoka tree is c. saprophytic a. Photosynthetic d. parasitic b. Parasitic c. Saprophytic d. Symbiont 7. Organisms which prepare food for themselves using simple naturally available raw materials are referred to as a. heterotrophs b. autotrophs c. parasites d. saprophytes 4

PRACTICE SHEET - 4 (PS-4) I. Answer the following: 1. Potato and ginger are both underground parts that store food. Where is the food prepared in these plants? 2. Photosynthesis requires chlorophyll, and a few other raw materials. Add the missing raw materials to the list given below: Water, minerals, sunlight/light energy, carbon dioxide. 3. A goat eats away all the leaves of a small plant (balsam). However, in a few days, new leaves could be seen sprouting in the plant again. How did the plant survive without leaves? 4. Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilizers during cultivation. Why? 5. Wheat dough, if left in the open, after a few days, starts to emit a foul smell and becomes unfit for use. Give reason. 6. Sunlight, chlorophyll, carbon dioxide, water and minerals are raw materials essential for photosynthesis. Do you know where they are available? Fill in the blanks with the appropriate sources. a. Available in the plant: _____________ b. Available in the soil: _____________ c. Available in the air: ______________ d. Available during day: ____________ 5

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option 8. When you observe leaves of plants, you find water droplets on them. Thus, loss of 1. ___________is present in green leaves. this excess water from plant body is called a. Oxygen _____________ . b. Carbon dioxide a. photosynthesis c. Chlorophyll b. transpiration d. Air c. respiration d. assimilation 2. Guard cells are ________ in shape. a. Cylindrical 9. Pitcher plant can prepare its own food using b. Bean chlorophyll. Even then it feeds on insects. What c. Spherical could be the reason? d. Irregular a. It has weak roots. b. It grows in a place where there is no sunlight. 3. ____________mode of nutrition is observed in c. It has inefficient leaves to prepare food. Cuscutaplant; hence it is called __________. d. The soil in which they live do not have enough a. Autotrophic, algae minerals and nutrients. b. Heterotrophic, insectivore c. Heterotrophic, parasite 10. What is the main difference between Algae and d. Autotrophic, fungi Cascuta? a. Algae cannot prepare food and cascuta prepare 4. Pipe like structure called vessels are present in food for algae which of the following to transport minerals and b. Cascuta does not have leaves, but algae have water to the leaves of a plant? c. Algae prepare their own food, but cascuta a. Roots depend on others for its food b. Stem d. Both are insectivorous plants c. Branches d. All of these II. Short answer questions 1. What plant is shown in the image? What are 5. Carbon dioxide + water ________ + ________. a. Glucose + Oxygen such plants called? Give reason. b. Glucose + Ozone c. Sucrose + Oxygen 2. When you look at a leaf through microscope, d. Sucrose + Ozone how does it look like? Represent section of a leaf in the form of a neat labelled diagram. 6. Plants take water and air through their _______ and ________. 3. If suppose, there are no plants on earth. What a. stem, stomata happens to the life on earth? b. roots, stem c. lenticels, loose tissues III. Long answer questions d. roots, stomata 1. Write a short note on symbiotic relationship 7. If you leave pickles, leather,clothes and other present in some organism. articles in hot and humid weather for long time, 2. Plants require nitrogen for their growth. then _________ grow on them. a. Algae Nitrogen is present in abundance in air. b. Fungi Explain how this nitrogen is made available for c. Moth plants. d. Lichens 6

SELF EVALUATION SHEET Marks: 15 Time: 30 Mins I. Fill in the blanks: (4 Marks) 2. Why are green plants called autotrophs? Leaves have a green pigment called (a)_______ which captures (b)_________ from sunlight. This (c)______________ is used in the process of (d)_________ 3. How is an insect digested in the pitcher plant? II. Can you give me a name: (3 Marks) a. I am tall tree but I cannot move. I am green and can prepare my own food. 4. How is a farmer benefitted from symbiotic relationship between rhizobium bacteria and legumes? b. I am small and I can fly. I disturb your sleep, bite you and suck your blood which is my food. c. I am white and soft. I grow well in the rainy season. Children pluck me from the ground and admire me. I absorb nutrients from decomposed dead parts of plants and animals in the soil. III. Answer the following questions: (8 Marks) 1. Wild animals like tiger, wolf, lion and leopard do not eat plants. Does this mean that they can survive without plants? Can you provide a suitable explanation? 7

2. Nutrition in Animals Learning Outcome • Illustrate human alimentary canal. • Describe the structure of alimentary canal in rumi- By the end of this chapter, you will be: • State the importance of digestion to an organism. nants. • Explain the structure of alimentary canal in man. • Explain the process of rumination. • Describe the process of digestion. • Explain the process of digestion in amoeba. Concept Map NUTRITION IN ANIMALS Digestion in Digestion in Digestion in man ruminants amoeba Digestive Process of Digestive Process of Process of system digestion system digestion digestion Keypoints • The stomach of ruminating animals has four chambers that help in digestion of cellulose. • The main steps of nutrition in animals are ingestion, digestion, absorption, assimilation and egestion. Keywords: Absorption, amino acid, amoeba, assimilation, bile, buccal cavity, canine, cellulose, • Human digestive system comprises of main organs digestion, egestion, fatty acid, food vacuole, gall and accessory organs. Bladder, glycerol, incisor, Ingestion, liver, milk teeth, molar, permanent teeth, oesophagus, • Mouth, oesophagus, stomach, small intestine, pancreas,premolar, pseudopodia, rumen, large intestine, rectum and anus are main organs. ruminant, rumination, salivary glands, villi, saliva. Liver and pancreas form the accessory glands. • Digestion of food begins in the mouth. • Mouth has salivary glands that secrete saliva. • Stomach has hydrochloric acid to kill microbes in food and digestive juices help in digesting proteins. • In the small intestine, digestive juices of small intestine, pancreas and bile from liver are poured. So complete digestion of carbohydrates, fats and proteins occur in small intestine. • Digested foods are absorbed by the finger like projections called villi in small intestine. • In the large intestine, water is reabsorbed along with useful substances. • Undigested food matter as feces is ejected through anus. 8

2. Nutrition in Animals Work Plan PRACTICE SHEET SIMULATION/ PS-1 VIDEO CONCEPT COVERAGE COVERAGE DETAILS PS-2 Human digestive system with teeth Digestion in man Digestive system Process of digestion Digestion in ruminants Digestive system Process of digestion Digestion In amoeba Process of digestion PS-3 Structure of Worksheet for “Nutrition in Animals” Evaluation with self- PS-4 digestive system check or Peer check* in grass eating PS-5 animals Self-evaluation Sheet 9

PRACTICE SHEET - 1 (PS-1) I. Fill in the blanks: 1. ___________ secretes bile juice. 2. The food is completely digested in _____________. 3. ______ teeth are used for biting and cutting food in humans. 4. Digestion of proteins begin in _________________. 5. Stomach secretes ___________________ acid. II. Say True or False. If false corrrect the statement. 1. Amoeba has special digestive organs for digestion. 2. Cow stores food in rumen. 3. Grass is rich in cellulose. 4. Digestive enzymes, present in the sac like structure between small intestine and large intestine, digest cellulose. 5. Digestion of protein starts in buccal cavity. PRACTICE SHEET - 2 (PS-2) I. Select appropriate terms for the description given below from the box: 1. Taking of digested food material by the walls of the small intestine. 2. End product of protein digestion. 3. The process where in absorbed substances are taken by different organs of the body to build up complex substances needed by them. 4. A juice that helps in emulsification of fats. 5. Mouth with salivary glands and dentition form this. 6. Teeth used for tearing food. 7. A type of carbohydrates found in plants. 8. Process of breaking down complex food into simpler ones. 9. The process of eliminating waste from the body. 10. End products of fat digestion. 11. A temporary structure that forms around the food in amoeba and helps in digestion. 12. Organ that stores bile juice. 13. Biting or cutting teeth. 14. Process of taking in food by the organisms. 15. Organ that secretes bile. 10

PRACTICE SHEET - 3 (PS-3) 7. Read the following statements with reference to the villi of small intestine. I. Choose the correct option. i. They have very thin walls. 1. Given below from (i) to (iv) are some food ii. They have a network of thin and small items. blood vessels close to the surface. i. Boiled and mashed potato iii. They have small pores through which food ii. Glucose solution can easily pass. iii. A slice of bread iv. They are finger-like projections. iv. Mustard oil Identify those statements which enable the Which of the above will give blue-black colour villi to absorb digested food. when tested with iodine? a. i, ii and iv a. i and ii b. ii, iii and iv b. i and iii c. iii and iv c. ii and iii d. i and iv d. iii and iv 2. Which of the following pair of teeth differ in 8. The false feet of amoeba are used for structure but are similar in function? a. Movement only. a. Canines and incisors. b. Capture of food only. b. Molars and premolars. c. Capture of food and movement. c. Incisors and molars. d. Exchange of gases only. d. Premolars and canines. 3. Read carefully the terms given below. 9. The enzymes present in the saliva convert Which of the following set is the correct a. Fats into fatty acids and glycerol. combination of organs that do not carry out b. Starch into simple sugars. any digestive functions? c. Proteins into amino acids. a. Oesophagus, large intestine, rectum d. Complex sugars into simple sugars. b. Buccal cavity, oesophagus, rectum c. Buccal cavity, oesophagus, large intestine 10. Cud is the name given to the food of d. Small Intestine, large intestine, rectum ruminants which is 4. The swallowed food moves downwards in a. Swallowed and undigested. the alimentary canal because of b. Swallowed and partially digested. a. Force provided by the muscular tongue. c. Properly chewed and partially digested. b. The flow of water taken with the food. d. Properly chewed and completely digested. c. Gravitational pull. d. The contraction of muscles in the wall of 11. Choose the correct order of terms that food pipe. describes the process of nutrition in 5. The acid present in the stomach ruminants. a. Kills the harmful bacteria that may enter a. Swallowing → partial digestion → chewing along with the food. of cud → complete digestion b. Protects the stomach lining from harmful b. Chewing of cud → swallowing → partial substances. digestion → complete digestion c. Digests starch into simpler sugars. c. Chewing of cud → swallowing → mixing with d. Makes the medium alkaline. digestive juices → digestion 6. The finger-like outgrowths of amoeba helps d. Swallowing → chewing and mixing → partial to ingest food. However, the finger-like digestion → complete digestion outgrowths of human intestine helps to a. Digest the fatty food substances. 12. Cellulose-rich food substances are good b. Make the food soluble. source of roughage in human beings because c. Absorb the digested food. a. Human beings do not have cellulose- d. Absorb the undigested food. digesting enzymes. b. Cellulose gets absorbed in the human blood and converts into fibres. c. The cellulose-digesting bacteria convert cellulose into fibres. d. Cellulose breaks down into smaller components which are egested as roughage. 11

PRACTICE SHEET - 4 (PS-4) I. Answer the following: 1. You were blindfolded and asked to identify the drinks provided in two different glasses. You could identify drink A as lime juice and B as bitter gourd juice. How could you do it inspite of being blindfolded? 2. Boojho took some grains of boiled rice in test tube ‘A’ and Paheli took boiled and chewed rice in test tube ‘B’. Both of them poured 1 – 2 drops of iodine solution into the test tube and observed the colour change. What colour change would they have observed? Give reasons for your answer. 3. ‘A’ got her gall bladder removed surgically as she was diagnosed with stones in her gall bladder. After the surgery, she faced problems in digestion of certain food items when consumed in bulk. Can you tell which kind of food items would they be and why? 4. Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why? 5. Boojho and Paheli were eating their food hurriedly so that they could go out and play during the recess. Suddenly, Boojho started coughing violently. Think of the reasons why he was coughing. 12

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option 8. Different organisms use different mode of feeding. Which of the following organism uses 1. The breakdown of complex components of food its sticky tongue to catch the prey? into simpler substances is called __________. a. Bird a. Respiration b. Snake b. Digestion c. Frog c. Feeding d. Monkey d. Swallowing 9. After completion of digestion in small intestine, 2. Which of the following teeth are associated with the proteins are broken into _________. chewing? a. Glucose a. Molars b. Amino acids b. Canines c. Fatty acids c. Incisors d. Glycerol d. Wisdom teeth 10. Choose the correct matching considering the 3. Which of the following plays an important role lower jaw of human: in the digestion of fats? a. Saliva Type of teeth Their Number b. Bile juice c. Mucous i) Canines a) 4 d. Pancreatic juice ii) Molars b) 2 4. Which of the following is not a part of human digestive system? iii) Incisors c) 6 a. Buccal cavity b. Oesophagus a. i) – c); ii) – b); iii) – a) c. Lungs d. Anus b. i) – a); ii) – c); iii) – b) 5. What is ingestion? c. i) – b); ii) – c); iii) – a) a. Undigested food b. Taking food into the body d. i) – b); ii) – a); iii) – c) c. Absorption of digested food d. Rejecting food II. Short answer questions 1. How are milk teeth different from permanent 6. Which part of digestive system secrets mucous? a. Mouth teeth? b. Stomach 2. Why do we get hiccups of cough while eating c. Liver d. Pancreas food? 3. Compare the teeth incisors and canines. 7. The stomachof which organism pops out through its mouth while feeding? III. Long answer questions a. Starfish 1. What is amoeba? What is the mode of feeding in b. Whale c. Octopus amoeba? d. Python 2. What would happen if a person does not have a tongue? How is tongue useful for us? Discuss. 13

SELF EVALUATION SHEET Marks: 15 Time: 30 Mins I. Fill in the blanks: (3 Marks) IV. Label the parts in the diagram. Use the clues given below. (4 Marks) 1. Digestion of all food components is completed by the ________ juice. 2. Large intestine absorbs _________ and some _________ from the undigested food. II. Match the following: (4 Marks) a. The largest gland in our body. b. The organ where protein digestion starts. COLUMN A COLUMN B c. The organ that releases digestive juice into a. Housefly i. Biting and chewing b. Cockroach ii. Suckling the small intestine. c. Mosquito iii. Sponging d. The organ where bile juice gets stored. d. Infants iv. Sucking III. Choose the odd one out from each group and give reasons: (2 Marks) 1. Liver, salivary gland, starch, gall bladder. V. Answer in complete sentences: (2 Marks) 1. How is food digested in amoeba? 2. Stomach, liver, pancreas, salivary gland 14

3. Fibre to Fabric Learning Outcome • Describe the life cycle of a silk moth. • Explain the process of obtaining silk from silk By the end of this chapter, you will be: • State the animals that yield wool. moth. • Define selective breeding. • Differentiate between a natural fibre and an • Define sericulture. • Explain the process of obtaining wool from fibre. artificial fibre. Concept Map FIBRE TO FABRIC WOOL SILK Animals that From fibres to Life cycle of From cocoon yield wool wool silk moth to silk Rearing and Processing Rearing silk Processing silk breeding of fibres into worms sheep wool Keypoints • Wool and silk are two natural fibres obtained from animals. • Wool fibers are obtained from sheep, goats, alpacas and even camel. • Wool fabric is soft to touch and provides warmth. • Silk is a natural fibre made from the cocoons of silk worms. • Silk moth is a large, white insect which passes through different stages in its life cycle-eggs, larva, pupa and moth. • Silk is smooth, soft and lustrous. Keywords: Cocoon, fleece, reeling, scouring, sericulture, shearing, silk moth, silkworm, sorting. 15

3. Fibre to Fabric Work Plan CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET PS-1 Wool • Animals that yield wool PS-2 • Rearing and breeding of sheep PS-3 • Processing fibres into wool PS-4 PS-5 Silk • Life cycle of silk moth • Rearing silk worms Self-evaluation Sheet • Processing silk Worksheet for “Fibre to Fabric” Evaluation with self- check or Peer check* 16

PRACTICE SHEET - 1 (PS-1) I. Fill in the blanks: 1. Wool is actually the ________ on the body of some animals. 2. A larva transforms into a/an ___________. 3. ___________ are placed in hot water to loosen the silk filaments. 4. The process of washing the skin in tanks to remove grease, dust and dirt is called ________. II. Match the terms with their meanings: Terms Meanings ANSWER 1. Shearing 2. Scouring a. Joining thin fibres together by machines to form one strand of yarn. 3. Sorting b. Washing wool with water containing soap/detergent and small amount of 4. Spinning alkali like soda as to remove dust and grease. 5. Sericulture c. Rearing of silkworms for production of silk. 6. Cocoon d. The stage in silkworm’s life cycle in which larva spins silk like threads around itself. e. Separating wool or fibres of different texture. f. Removing wool from an animal by scissors, hand blades or electric machines. PRACTICE SHEET - 2 (PS-2) I. Say True or False: 1. Wool burns easily. 2. Silk is a plant fibre. 3. Amount of air trapped by wool is more than cotton fibres. 4. Longer fibres are made into wool for sweaters. 5. Rearing of silk worms for commercial purpose is called pisciculture. II. The pictures depict the life cycle of a silk moth. Rearrange the pictures in an appropriate order and select appropriate descriptions for the pictures and rewrite them in correct order. A BC D Male Female 17

PRACTICE SHEET - 3 (PS-3) 9. Which of the following is not a type of silk? a. Mulberry silk I. Choose the correct option: b. Tassar silk 1. Which of the following fibres is used for c. Mooga silk making camel wool? d. Moth silk a. Coarse beard hair b. Soft undercoat 10. Paheli wanted to buy a gift made of animal c. Coarse under coat fibre, obtained without killing the animal. d. None of these. Which of the following would be the right gift 2. In which of the following states of India, are for her to buy? sheep reared? a. Woollen shawl a. Uttarakhand b. Silk scarf b. Himachal Pradesh c. Animal fur cap c. Sikkim d. Leather jacket d. All of the above. 3. The main source of wool is 11. Wool fibre cannot be obtained from which of a. Alpaca the following? b. Angoara goat a. Goat c. Sheep b. Llama d. Angora rabbit c. Alpaca 4. The stage in which silk thread is obtained d. Moth from silkworm is a. Egg 12. Selective breeding is a process of b. Larva a. Selecting the offsprings with desired c. Pupa properties. d. Adult b. Selecting the parents with desired 5. The food of silkworms is leaves of properties. a. Maple c. Selecting an area for breeding. b. Mulberry d. Selecting fine hair for good quality wool. c. Neem d. All of these. 13. The general process that takes place at a 6. Wool is obtained from sheep shearing shed is a. Sheep a. Removal of fleece. b. Goat b. Separating hair of different textures. c. Camel c. Washing of sheep fibre to remove grease. d. All of these. d. Rolling of sheep fibre into yarn. 7. Silk fibre is obtained from a. Sheep fleece b. Cocoon c. Cotton boll d. Jute stalk 8. The process of rearing silkworms for obtaining silk is called a. Silviculture b. Sericulture c. Silk culture d. Vermiculture 18

PRACTICE SHEET - 4 (PS-4) I Answer the following: 1. How does the hair of animals help in keeping their body warm? 2. Various steps involved to obtain wool from fleece are given below: i. Picking out burrs ii. Dyeing in various colours iii. Shearing iv. Scouring v. Sorting. Write the steps in correct sequence in which they are carried out. 3. Some words related with silk are jumbled up. Write them in their correct form. a. Tureculrise b. Wilsmork c. Belmurry d. Ringlee 4. Figure shows three rings of circles with letters in them. Some of these letters in each ring can form the name of one wool yielding animal. Find the names of these animals. 5. Steps for the production of silk are given below in a jumbled order. Arrange them in their proper sequence. a. Eggs are warmed to a suitable temperature for the larvae to hatch from eggs. b. Fibers are taken out from the cocoon. c. After 25 to 30 days, the caterpillars stop eating and start spinning cocoons. d. The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves. e. Female silk moths lay eggs. f. Cocoons are kept under the sun or boiled in water. 19

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option 8. At which of the following stages of silk moth, silk fibre is obtained? 1. Which of the following animals yield wool for a. Eggs us? b. Cocoon a. Sheep c. Silk moth b. Goat d. Silkworm c. Yak d. All of these 9. Choose the correct matching: 2. What is the process of taking out threads from A B the cocoon for use as silk called? i) Fleece called Mohair is a) Llamaand Alpaca a. Reeling the silk obtained from b. Rearing c. Shearing ii) Fine shawls of Kashmiri b) Angora goats d. Scouring goats are called 3. Silk yarn yielded by silk moth can be in iii) Camel fur as wool is c) Pashmina ___________ texture. used in a. Coarse b. Smooth a. i) – b); ii) – a); iii) – c) c. Shiny b. i) – b); ii) – c); iii) – a) d. All of these c. i) – c); ii) – a); iii) – b) d. i) – a); ii) – c); iii) – b) 4. Which of the following countries lead the world in silk production? 10. Which of the following is the correct flow chart a. India of processing of fibre into wool? b. China c. Australia a. Shea ring Sortin g Scourin g Cleaning of burrs d. New Zealand Rolling Dyeing 5. Which of the following processes is shown in the image? b. Scour ing Sheari ng Sorting Cl eaning of burrs a. Shearing Rolling Dyeing b. Rolling c. Scouring c. Shear ing Scouri ng Sorting Cl eaning of burrs d. Dyeing Rolling Dyeing 6. The number of days for which caterpillars eat d. Shearing Scouring Sorting Cleaning of burrs mulberry leaves is _____. a. 15 to 20 days Dyeing Rolling b. 15 to 30 days c. 20 to 35 days d. 25 to 30 days 7. In India, women are significantly involved in which kind of industries related to silk production among the given? a. Rearing of silkworms b. Reeling of silk from cocoons c. Processing of raw silk into fabrics d. All of these 20

PRACTICE SHEET - 5 (PS-5) II. Short answer questions 1. Mark the states in the given India map; i) Rajasthan and Gujarat where you find camel ii) Himachal Pradesh where you find yak 2. How is selective breading done? Explain taking sheep as an example. 3. Why do people working in wool industry suffer from health hazards? What are those hazards? III. Long answer questions 1. Write a short notes on ‘Rearing of silkworms.’ 2. The process shearing is not done during winter. Then when is it done? Also shearing does not hurt the sheep. Justify by giving reasons. 21

SELF EVALUATION SHEET Marks: 15 Time: 30 Mins I. Fill in the blanks: (7 Marks) III. Answer the following: (4 Marks) The ____(a)___ silk moth lays ___(b)___, 1. Paheli went to the market to buy sarees from which hatch ____(c)___ called ___ for her mother. She took out a thread from (d)____ or ___(e)____. They grow in size and the edge of the two sarees shown by the when the caterpillar is ready to enter the shopkeeper and burnt them. One thread next stage of its life history called ___(f)____, burnt with a smell of burning hair and the it first weaves a covering to hold itself, which other burnt with the smell of burning paper. is known as a ___(g)____. Which thread is from a pure cotton saree and which one from a pure silk saree? Give reason for your answer. II. Match the following: (4 Marks) ANSWER Column A Column B a. Yak wool Sheared hair b. Angora goats Silkworm c. Mulberry Tibet and Ladakh leaves Jammu and d. Scouring Kashmir 22

4. Heat Learning Outcome By the end of this chapter, you will be: • Explain different modes of heat transfer. • Define temperature. • Cite examples for different modes of heat transfer. • Recognize three scales of temperature-Celcius, • Relate convection to formation of sea breeze and Fahrenheit and Kelvin scales. land breeze. • Read the thermometer-clinical and laboratory. • Analyze the clothing patterns with respect to season. Concept Map HEAT Heat or cold Transfer of Clothes we Measuring heat wear Vs temperature Seasons Transfer of Heat Scales of Reading a Types of Conduction Convection Radiation temperature thermometer Thermometer Clinical Laboratory Keypoints • Through radiation, sunrays reach the earth and have made this planet warm and convenient for life • Heat flows from a body at a higher temperature to forms to survive. a body at a lower temperature. Keywords: Celsius scale, conduction, conductor, • Celcius, Fahrenheit and Kelvin are the common convection, insulator, land breeze, radiation, sea temperature scales. breeze, temperature, thermometer. • Heat transfer from one body to another can take place by the process of conduction, convection and radiation. • In solids, heat is transferred by conduction. • In liquids and gases, heat is transferred by convection. • Conduction and convection require a medium for heat to flow, whereas radiation can take place even in vacuum. • Metals are usually good conductors of heat and are called conductors. Insulators are the substances that do not conduct heat. Plastic, paper, fur, cloth and wood are examples of insulators. • Sea breeze and land breeze are examples of convection currents in gases. 23

4. Heat Work Plan PRACTICE SHEET SIMULATION/ VIDEO CONCEPT COVERAGE COVERAGE DETAILS Heat or cold Measuring temperature PS-1 Thermometers: Scales of temperature Clinical lab. Transfer of heat Reading a thermometer Types of Thermometer PS-2 Clothes we wear Vs • Conduction Seasons • Convection PS-3 Activity to Worksheet for “Heat” • Radiation demonstrate Evaluation with self- transfer of heat in a check or Peer check* metal strip PS-4 PS-5 Convection of heat in water and air Self-evaluation Sheet 24

PRACTICE SHEET - 1 (PS-1) I. Fill in the blanks selecting appropriate words from the box. kink 212°F 0°C to 110°C bad conduction radiation 1000F 37°C laboratory clinical good dark mercury copper light convection 1. Metal used in the thermometer is _____________. 2. The __________ in the thermometer prevents the backflow of mercury into the bulb. 3. The boiling point of water on Fahrenheit scale is ____________. 4. The range of temperature in a laboratory thermometer is ____________. 5. Water is a __________ conductor of heat. 6. We receive sun’s light by _________________. 7. Land breeze is formed due to _________________. 8. In summer, we wear ______________ coloured clothes. 9. Temperature of a normal human body is ___________. 10. When you have fever, your doctor uses a ________ thermometer to find out your body temperature. II. Say True or False: 1. Air is a good conductor of heat. 2. Actual movement of molecules takes place in convection. 3. When water at 50°C is poured at a pan heated to 80°C, heat flows from water to pan. 4. A clinical thermometer can measure the temperature of ice. 5. Conduction takes place only when two objects are not in contact with each other. 25

PRACTICE SHEET - 2 (PS-2) I. Match the Following: COLUMN II Actual movement of molecules COLUMN I No medium required. 1. Convection current Instrument to measure body temperatures. 2. Conduction Two bodies in contact 3. Insulators Rubber, cork, plastic, wood 4. Clinical thermometer Gold, silver, copper, iron 5. G ood absorbers of heat Black colours and dark colours 6. Convection Land breeze and sea breeze 7. Radiation 8. Good conductors II. Select the appropriate word for the descriptions given below: Heat Insulator Radiation Conductor Thermometer Convection Conduction Clinical thermometer Temperature Laboratory thermometer 1. Degree of hotness of a body. 2. An instrument used to measure the temperature. 3. A thermometer used to measure the human body temperature. 4. A thermometer used in the laboratories to measure the temperature of chemicals. 5. Form of energy used to do work. 6. Heat transfer through a substance without actual movement of molecules. 7. A substance through which heat can flow easily. 8. Heat transfer by actual movement of molecules of the substance. 9. Transfer of heat without the need of any material medium. 10. A substance which blocks heat. 26

PRACTICE SHEET - 3 (PS-3) 9. A marble tile would feel cold as compared to a wooden tile on a winter morning, because I. Choose the correct option: the marble tile 1. Best conductor of heat is a. Is a better conductor of heat than the a. Gold wooden tile. b. Silver b. Is polished while wooden tile is not c. Copper polished. d. Mercury c. Reflects more heat than wooden tile. 2. The thermometer used to measure body d. Is a poor conductor of heat than the temperature is wooden tile. a. Clinical thermometer b. Laboratory thermometer 10. A beggar wrapped himself with a few layers c. Kelvin thermometer of newspaper on a cold winter night. This d. Any of the above. helped him to keep himself warm because 3. In solids, transfer of heat takes place by a. Friction between the layers of newspaper a. Convection produces heat. b. Conduction b. Air trapped between the layers of c. Radiation newspaper is a bad conductor of heat. d. All of these. c. Newspaper is a conductor of heat. 4. Convection of heat takes place in d. Newspaper is at a higher temperature than a. Only solids the temperature of the surrounding. b. Only liquids c. Liquids and solids d. Liquids and gases 5. Which of the following is an insulator? a. Aluminum b. Bakelite c. Mercury d. Steel 6. Temperature is measured in a. Calories b. Celsius c. Joule d. All of these 7. Heat energy will flow from body “A” to body “B”, if a. B is at a higher temperature than A. b. A is at a higher temperature than B c. Both are at the same temperature. d. No heat flows. 8. Dark coloured clothes keep the body warm because they are a. Good absorbers of heat b. Bad absorbers of heat c. Neither good nor bad absorbers of heat d. None of these. 27

PRACTICE SHEET - 4 (PS-4) I. Answer the following questions: 1. Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why. 2. To keep her soup warm, Paheli wrapped the container in which it was kept, with a woollen cloth. Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer. 3. In a mercury thermometer, the level of mercury rises when its bulb comes in contact with a hot object. What is the reason for this rise in the level of mercury? 4. For setting curd, a small amount of curd is added to warm milk. The microbes present in the curd help in setting if the temperature of the mixture remains approximately between 35°C to 40°C. At places, where room temperature remains much below the range, setting of curd becomes difficult. Suggest a way to set curd in such a situation. 5. You may have noticed that a few sharp jerks are given to clinical thermometer before using it. Why is it done so? 6. Why is it advised not to hold the thermometer by its bulb while reading it? 7. While constructing a house in a coastal area, in which direction should the windows preferably face and why? 28

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option 7. Now a days, we see copper-bottomed stainless-steel vessels used in kitchen. 1. The process by which we get the sun’s heat is What could be the reason? called _______. a. To provide rich look a. Conduction b. Copper is better conductor of heat than b. Convection stainless steel c. Absorption c. The copper-bottomed vessels are cheaper d. Radiation d. Easy to clean 2. What coloured clothes are suggested to wear in 8. We carry thermo flasks with us for later use of summer? hot or cold substance. How does it prevent loss a. White or gain of heat? b. Light coloured a. By convection c. Black b. By conduction d. Either (A) or (B) c. By radiation d. All of these 3. Land breeze means: a. The cool air that moves from the land towards 9. To construct buildings, that are not affected the sea much by heat and cold outside: b. The air that moves from the sea towards the a. Outer walls of building should have trapped land layers of air c. The hot air that moves from the land towards b. Use hollowbricks the mountain c. Use wood to construct walls d. The air that is present in the atmosphere d. Both (A) and (B) 4. What is clinical thermometer? 10. Boojho wanted to buy ice. The shopkeeper a. The one used to measure the temperature of a wrapped ice in a gunny bag and gave him. What substance could be the reason? b. The one that measures our body temperature a. So that ice does not melt immediately c. The one that measures the weather b. For safety d. The one that measures the density c. To carry d. Not others to make it out 5. The figure demonstrates: a. Transfer of heat by II. Short answer questions convection in water 1. A metal chair and a wooden chair are kept in the b. Transfer of heat by conduction in water sun. Which chair will become hot faster? Why? c. Transfer of heat by 2. What do you observe in the image? Give reason. convection in air d. Transfer of heat by 3. Why do you think the handles of pressure absorption in water cooker and fry pans are made of thick plastic and why not the same material is used as that of 6. A clinical thermometer readstemperature from: pressure cooker? a. 35°C to 42°C b. 37°C to 45°C c. 0°C to 100°C d. 40°C to 65°C 29

PRACTICE SHEET - 5 (PS-5) III. Long answer questions 1. Write an experiment to demonstrate transfer of heat by conduction. 2. Give reasons for the following: i) A wooden stirrer is better than a stainless-steel stirrer. ii) A cold drink bottle is wrapped with a jute bag while travelling. iii) Clinical thermometer is not hold at the bulb while noting the temperature. iv) China clay cups are used for serving hot tea. v) Hot tea left for a while becomes cold. 30

SELF EVALUATION SHEET Marks: 15 Time: 30 Mins I. Fill in the blanks: (3 Marks) 3. Which mode of heat transfer requires no medium? 1. Hotness of an object is determined by its _____________. 2. Temperature is measured in degree IV. Answer in two or three sentences: (6 Marks) ____________. 1. Why are clinical thermometers not used to measure boiling point of water? 3. Land sea breeze blows during _______________. II. Say true or false: (3 Marks) 1. Temperature of boiling water cannot be 2. At a camp site, there are tents of two shades measured using a clinical thermometer. – one made with black fabric and the other with white fabric. Which one will you prefer 2. While reading the temperature in a clinical for resting on a hot summer afternoon? Give thermometer, thermometer has to be kept reason for your choice. Would you like to inside the smouth. prefer the same tent during winter? 3. The flow of cool air from sea towards the land is called sea breeze. III. Answer in a sentence: (3 Marks) 1. What is the scale used for measuring temperature for scientific purposes? 2. What is the function of kink in a clinical thermometer? 31

5. Acids, Bases and Salts Learning Outcome • State the uses of bases. • Define salt. By the end of this chapter, you will be: • Identify different types of indicators. • Define acid. • Define neutralization reaction. • Classify acids into organic and mineral acids. • Explain the applications of neutralization reaction • Cite examples for acids. • State the uses of acids. in our day to day life. • Define a base. • Cite examples for bases. Concept Map ACIDS, BASES AND SALTS ACIDS BASES SALTS INDICATORS Examples Examples Examples Natural Uses Uses Neutralization Synthetic reaction Keypoints • Acids are corrosive in nature and sour to taste. • Hydrogen gas is released when acids react with metals. • Bases react with acids and form salt and water. • Some bases are soluble in water are called alkalis. • Bases turn red litmus blue, whereas acids turn blue litmus red. • In a neutralisation reaction, an acid and a base react together to form salt and water. • Salt solutions can conduct electricity. • Hydrogen gas is liberated when metals react with acids. Keywords: Acid, acidic, base, basic, indicator, neutral, neutralization, salt. 32

5. Acids, Bases and Salts Work Plan PRACTICE SHEET SIMULATION/ VIDEO CONCEPT COVERAGE COVERAGE DETAILS PS-1 Testing whether lemon PS-2 juice is acid or base by Acids • Examples PS-3 litmus paper • Uses PS-4 Using China rose as PS-5 indicator Bases • Examples Self-evaluation • Uses Sheet Study process of neutralisation by using HCl Salts • Examples and NaOH with the help of • Neutralization reaction phenolphthalein Indicators • Natural • Synthetic Worksheet for “Acids, Bases and Salts” Evaluation with self- check or Peer check* 33

PRACTICE SHEET - 1 (PS-1) I. Fill in the blanks: 1. The presence of a/an ___________ makes a substance taste sour. 2. Acids react with bases to form _________ and _______________ 3. Sodium hydroxide + Hydrochloric acid → ___________+ _____________ 4. _________ and _____________ are synthetic indicators. 5. Basic solution turns _______ litmus to blue______________. II. Where am i found in? ACID/BASE FOUND IN Acetic acid Formic acid Citric acid Lactic acid Oxalic acid Calcium hydroxide Ammonium hydroxide Sodium hydroxide Magnesium hydroxide PRACTICE SHEET - 2 (PS-2) I. Complete the following table: Indicator that can Initial colour of Final colour of be used the test solution the test solution Sl.No Test solution Blue litmus 1 Lemon juice Phenolp­ hthalein 2 Milk of magnesia 3 Soda water Blue litmus 4 Baking soda 5 Vinegar Red litmus 6 Orange juice 7 Soap solution Blue litmus 8 Shampoo (dilute) 9 ENO fruit salt Blue litmus Phenolp­ hthalein Turmeric solution Phenol­phthalein II. Complete the following table: Indicator Acidic medium Colour in Neutral medium Red Basic medium Blue litmus Red Red litmus Colourless Phenolp­ hthalein Orange Methyl orange 34

PRACTICE SHEET - 3 (PS-3) 8. A solution changes the colour of turmeric indicator from yellow to red. The solution is I. Choose the corrrect option: a. Basic 1. The correct way of making a solution of acid b. Acidic in water is to c. Neutral a. Add water to acid. d. Either neutral or acidic b. Add acid to water. c. Mix acid and water simultaneously. 9. Which of the following set of substances d. Add water to acid in a shallow container. contain acids? 2. Products of a neutralization reaction are a. Grapes, lime water always b. Vinegar, soap a. An acid and a base. c. Curd, milk of magnesia b. An acid and a salt. d. Curd, vinegar c. A salt and water. d. A salt and a base. 10. On adding phenolphthalein indicator to a 3. Turmeric is a natural indicator. On adding colourless solution, no change is observed. its paste to acid and base separately, which What is the nature of this solution? colours would be observed a. Basic a. Yellow in both acid and base. b. Either acidic or basic b. Yellow in acid and red in base. c. Either acidic or neutral c. Pink in acid and yellow in base. d. Either basic or neutral d. Red in acid and blue in base. 4. Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions, respectively are a. Red and blue. b. Blue and red. c. Pink and colourless. d. Colourless and pink 5. When the soil is too basic, plants do not grow well in it. To improve its quality, what must be added to the soil? a. Organic matter b. Quick lime c. Slaked lime d. Calamine solution 6. ‘Litmus’, a natural dye is an extract of which of the following? a. China rose (Gudhal) b. Beetroot c. Lichen d. Blue berries (Jamun) 7. Neutralization reaction is a a. Physical and reversible change. b. Physical change that cannot be reversed. c. Chemical and reversible change. d. Chemical change that cannot be reversed. 35

PRACTICE SHEET - 4 (PS-4) I. Answer the following: 1. Look at the given reaction. Hydrochloric acid + Sodium hydroxide (base) → Sodium chloride (salt) + Water Sodium chloride formed in this reaction remains in solution form. Can we get solid sodium chloride from this solution? Suggest a method (if any). 2. While playing in a park, a child was stung by a wasp. Some elders suggested applying paste of baking soda and others lemon juice as remedy. Which remedy do you think is appropriate and why? 3. Form a sentence using the following words – baking soda, ant bite, moist, effect, neutralised, rubbing. 4. Boojho, Paheli and their friend Golu were provided with a test tube, each containing China rose solution which was pink in colour. Boojho added two drops of solution ‘A’ in his test tube and got dark pink colour. Paheli added 2 drops of solution ‘B’ to her test tube and got green colour. Golu added 2 drops of solution ‘C’ but could not get any change in colour. Suggest the possible cause for the variation in their results. 5. A farmer was unhappy because of his low crop yield. He discussed the problem with an agricultural scientist and realised that the soil of his field was either too acidic or too basic. What remedy would you suggest the farmer to neutralize the soil? 36

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option 8. Which substance when tested with red and blue litmus paper doesn’t change its colour? 1. Special substances that are used to test whether a. Milk the given substance is acidic or basic are called b. Mineral water ___________. c. Lime water a. Salts d. Butter milk b. Soaps c. Indicators 9. The acidic liquid injected by an ant bite is d. Lichens neutralised by rubbing the area with ______. a. Baking soda 2. Milk of magnesia contains: b. Calamine solution a. Magnesium hydroxide c. Phenolphthalein b. Hydrogen peroxide d. Either (A) or (B) c. Nitrogen dioxide d. Calcium chloride 10. Plants do not grow well when the soil is either too acidic or too basic. When the soil is too acid- 3. Natural indicator(s) among the following is/ are: ic, it is treated with bases like ____________. a. Turmeric a. quick lime b. Litmus b. slakedlime c. China Rose petals c. Compost d. All of these d. Either (A) or (B) 4. In which of the following solutions does, phe- II. Short answer questions nolphthalein remains colourless? 1. Why are the inner walls of vessels made up of a. Salt solution b. Acidic solution brass and copper coated with another sub- c. Basic solution stance? d. Neutral solution 2. Write some uses of acids in our daily life. 5. Which of the following is a basic in na- ture? 3. Sugar is neutral, so Raju thought that it is a salt. a. Soap solution Do you agree with him? Write three reasons to b. Milk support your answer. c. Lemon juice d. Tamarind III. Long answer questions 1. What is an indicator? What are natural 6. Which of the following indicators turn acidic solutions to dark pink (magenta) and basic solu- indicators? Write a short note on them. tions to green. a. Turmeric 2. Why and how is acid rain caused? Identify the b. China rose effects of acid rain. c. Litmus d. Phenolphthalein 7. While making lemon rice, when Paheli added lemon juice on to salt, she found the salt turned grey in colour. What could be the reason? a. Salt is impure b. Lemon is spoiled c. Lemon juice is acidic d. Salt is basic 37

SELF EVALUATION SHEET Marks: 15 Time: 30 Mins I. Say true or false: (4 Marks) IV. Answer the following: (4 Marks) a. All substances are either acidic or basic. 1. You are provided with three test tubes A, B and C as shown in Figure with different b. A compound if acidic will turn all indicators liquids. What will you observe when you put red. c. Lime water turns red litmus blue. d. Common salt dissolved in water turns blue A BC litmus red. Solution of Soap solution Pure water tartatic acid II. Match the following: (5 Marks) a. A piece of blue litmus paper in each test COLUMN I COLUMN II tube? 1. Tartaric acid a. Soap b. A piece of red litmus paper in each test 2. Calcium hydroxide b. Curd 3. Formic acid c. Unripe mangoes tube? 4. Sodium hydroxide d. Ant’s sting c. A few drops of phenolphthalein solution to 5. Lactic acid e. Lime water each test tube? Solution Effect on Effect on Effect on Tartaric blue litmus red litmus phenol­ acid phthalein III. Give reasons: (2 Marks) 1. Acids should be handled with care. Soap 2. A farmer uses organic manure to the alkaline Pure water soil in the field. 2. Paheli observed that most of the fish in the pond of her village were gradually dying. She also observed that the waste of a factory in their village is flowing into the pond which probably caused the fish to die. a. Explain why the fish were dying. b. If the factory waste is acidic in nature, how can it be neutralised? 38