202110728-PERFORM-STUDENT-WORKBOOK-SCIENCE-G10-FY_Optimized

practice workbook SCIENCE Grade 10 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 10. 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 • Academic Plan - Teaching and Assessment • Planning Tool • Assessment Pattern: 40 Marks • Assessment Pattern: 80 Marks • Syllabus & Timeline for Assessment Page 1: 1. Chemical Reactions and Equations Page 9: 2. Acid, Bases and Salts Page 17: 3. Metals and Non-metals Page 25: 4. Carbon and its Compounds Page 32: 5. Periodic Classification of Elements Page 39: 6. Life Processes Page 48: 7. Control and Coordination Page 55: 8. How do Organisms Reproduce? Page 63: 9. Heredity and Evolution Page 70: 10. Light - Reflection and Refraction Page 79; 11. The Human Eye and the Colorful World Page 87: 12. Electricity Page 98: 13. Magnetic Effects of Electric Current Page 107: 14. Sources of Energy Page 115: 15. Our Environment Page 122: 16. Sustainable Management of Natural Resources







ASSESSMENT PATTERN Marks: 40 Grade 10/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 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).

ASSESSMENT PATTERN Marks: 80 Grade 10/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 Remembering • Remembering • 28 5 • Remembering • Remembering • 29 5 Understanding • Understanding • 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 Grade 10/Science CHAPTERS PT-1 TE-1 PT-2 MOCK Chapter 1: Chemical Reactions and Equations ✓✓ ✓ ✓ Chapter 2: Acid, Bases and Salts ✓✓ ✓ Chapter 3: Metals and Non-metals ✓ ✓ Chapter 4: Carbon and its Compounds ✓ ✓ Chapter 5: Periodic Classification of Elements ✓ ✓ ✓ Chapter 6: Life Processes ✓ ✓ Chapter 7: Control and Coordination ✓✓ ✓ ✓ Chapter 8: How do Organisms Reproduce? ✓ ✓ Chapter 9: Heredity and Evolution ✓ Chapter 10: Light - Reflection and Refraction ✓✓ ✓ Chapter 11: The Human Eye and the Colorful World ✓ Chapter 12: Electricity ✓ ✓ Chapter 13: Magnetic Effects of Electric Current ✓ Chapter 14: Sources of Energy ✓ ✓ Chapter 15: Our Environment ✓ Chapter 16: Management of Natural Resources ✓ Assessment Timeline Periodic Test-1 : 1st July to 31st July Term 1 Exam : 23rd September to 21 October Periodic Test-2 : 16th December to 13th January Mock Exam : 17th February to 9th March



LESSON WISE PRACTICESHEETS (This section has a set of practice questions grouped into different sheets based on different concepts. By solving these questions you will strengthen your subject knowledge. A self-evaluation sheet is provided at the end of every lesson.)



1. Chemical Reactions and Equations Learning Outcomes combination reaction, decomposition reaction, displacement reaction and double At the end of this lesson, students will be able to: decomposition reaction. • Write the word equations for given chemical • Differentiate between oxidation and reduction reaction. reaction. • Give examples for each types of reaction. • Balance the given chemical equations. • Write balanced chemical equations for given chemical reaction. • Classify the chemical reaction as Concept Map Chemical reaction and equation Chemical equation Types of chemical reaction  Combination reaction  Decomposition reaction  Displacement reaction  Double displacement reaction  Oxidation reaction  Reduction reaction Key Points • Chemical reaction is a process in which atoms of the • If a substance gains oxygen during reaction, it is said same or different elements rearrange themselves to to be oxidized. If a substance loses oxygen during form a new substance. reaction, it is said to be reduced. • As per law of conservation of mass, mass can nei- • When a metal is attacked by substances around it ther be created nor be destroyed. The total mass of such as moisture, acids, etc., it is said to corrode elements in products has to equal to the total mass and this process is called corrosion. The black coat- of elements present in the reactants. ing on silver and the green coating on copper are • In combination reaction, two or more reactants other examples of corrosion. combine to give a single product. • When the substance containing oils and fats are ex- • A single reactant breaks into two or more products posed to air, they get oxidized and become rancid in a decomposition reaction. due to which their smell, taste and colour change. • A displacement reaction is a reaction in which an This process is known as rancidity. atom, or a group of atoms, present in a molecule is Key words: Reaction, equation, combination, decom- displaced by another atom. position, displacement, double - displacement, oxida- • Double displacement is the reaction in which two tion, reduction, corrosion, rancidity compounds react by an exchange of ions to form two new compounds. 1

1. Chemical Reactions and Equations Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SIMULATION/ SHEET VIDEO Chemical equations • Writing word PS-1 Burning of a Magnesium equation Ribbon • Writing chemical Lead Nitrate with equation Potassium Iodide HCL with Zinc Granules • Balancing the Combination Reaction chemical equation Decomposition Types of chemical • Combination PS-2 Reaction reactions reaction Displacement Reaction Double Displacement • Decomposition reaction Reaction • Displacement reaction • Double displacement reaction Types of chemical • Oxidation PS-3 reactions reaction • Reduction reaction • Corrosion • Rancidity Worksheet for \"Chemical Reactions and Equations\" PS-4 Evaluation with self- Self-evaluation check or Peer check* Sheet *Administering self-evaluation at the end of a chapter is a good practice • Teacher discusses the correct answer or displays it using an overhead projector and asks the students to exchange their sheets or books to check and correct each other’s work. • The teacher may only need to do a sample check of students’ work. • Typically takes 10 – 15 mins. 2

PRACTICE SHEET - 1 (PS-1) I.  Balance each of these equations. 1. KI + Cl₂ → KCl + I₂ 2. Mg(NO₃)₂→ MgO + NO₂ + O₂ 3. FeCl₃ + NaOH → Fe(OH)₃ + NaCl 4. Zn(OH)₂ + HCl → ZnCl₂ + H₂O 5. Fe₂O₃ + Al → Al₂O₃ + Fe II.  Write balanced equations for each of these word equations. 1. Calcium carbonate decomposes on heating to form carbon dioxide and calcium oxide 2. Lead reacts with sulphuric acid to form lead(II) sulphate, sulphur dioxide and water. 3. Sodium reacts with silver(I) nitrate to give silver(I) chloride and sodium nitrate. 4. Zinc sulphide reacts with oxygen to form zinc oxide and sulphur dioxide. III.  Answer these questions. 1. List the changes which indicate that chemical reaction has taken place. 2. State the law of conservation of mass. 3

PRACTICE SHEET - 2 (PS-2) (b) What is the colour of the precipitate formed? (c) Write a balanced chemical equation to repre- I.  Write the products of each of these reactions. sent the above reaction. 6. The experimental set-up of electrolysis of water 1. Calcium oxide + water→ is shown in the diagram below. Label the parts 2. Methane + oxygen→ (A, B, C and D) and identify the type of the reac- 3. Lead + copper chloride → tion. 4. Sodium sulphate + barium chloride → 7. Shivani took a few grams of ferrous sulphate II.  Choose the correct answer from the options crystals in a test tube and heated it. Mention the given below. changes she would observe and write the bal- anced chemical equation for this reaction. 1. On immersing an iron nail in CuSO4 solution for few minutes, you will observe 8. Shyam added 1g of ammonium chloride to 2 g of a. No reaction takes place barium hydroxide. Write the expected products b. The colour of solution fades away and identify whether this reaction is exothermic c. The surface of iron nails acquires a black coat- or endothermic? ing d. The colour of solution changes to green 2. In which of the following, will heat energy be evolved? a. Reaction of glucose with oxygen b. Reaction of iron with copper sulphate c. Decomposition of AgBr in the presence of sun- light d. Both (a) and (b) 3. When crystals of lead nitrate are heated strongly in a dry test tube a. blue fumes evolve b. brown residue evolves c. white fumes appear in the tube d. yellow residue evolves 4. Which of these substances is used for black and white photography? a. sodium bromide b. silver bromide c. potassium bromide d. lead sulphate II.  Answer each of these questions. 1. What is thermal decomposition? 2. State the difference between exothermic and en- dothermic reaction. 3. Write any one use of calcium oxide and calcium hydroxide. 4. Which forms of energy are absorbed during a chemical reaction? 5. When a solution of potassium iodide is added to a solution of lead nitrate in a test tube, a reac- tion takes place. (a) What type of reaction is this? 4

PRACTICE SHEET - 3 (PS-3) 8. Which of the following statements is/are false for reduction reaction? I.  Choose the correct answer from the options a. Addition of an anion given below. b. Addition of hydrogen atom. c. Addition of cation 1. A redox reaction is one in which d. None of these a. Both the substances are reduced b. Both the substances are oxidized II.  Answer these questions. c. An acid is neutralized by the base d. One substance is oxidized while the other is re- 1. Why are chips packets flushed with nitrogen duced gas? 2. In the equation, NaOH + HNO_3 3→NaNO_3+ 2. How does corrosion affect our economy? H_2 O nitric acid is acting as 3. Reaction of copper oxide with hydrogen is an a. An oxidizing agent b. A base example of redox reaction. Explain why. c. A reducing agent d. A dehydrating agent 3. Rusting of an iron is an example of a. Reduction b. Ionization c. Oxidation d. Dissociation 4. Reduction is a process which involves a. Addition of oxygen b. Removal of hydrogen c. Removal of oxygen d. All are correct 5. Which of the following does not corrode when exposed to atmosphere? a. Iron b. Copper c. Gold d. Silver 6. In the reaction PbO+C→Pb+CO. a. PbO is oxidized b. C acts as an oxidizing agent. c. C acts as a reducing agent. d. This reaction does not represent a redox reac- tion. 7. In the process of burning magnesium in air, magnesium undergoes a. Reduction b. Sublimation c. Oxidation d. All of these 5

PRACTICE SHEET - 4 (PS-4) I. Choose the correct option. 1. The reaction mixture becomes warm in a. Precipitation reaction b. Exothermic reaction c. Combination reaction d. Endothermic reaction 2. Limestone on heating gives a. Washing soda b. Plaster of Paris c. Quicklime d. Slaked lime 3. The insoluble substance is formed in a. Combination reaction b. Exothermic reaction c. Endothermic reaction d. Precipitation reaction 4. To study the reaction of Zinc with sodium hydroxide a. Add dilute NaOH to Zinc granules and do not heat. b. Add dilute NaOH to Zinc granules and slowly heat. c. Add NaOH pellets to Zinc granules. d. Add NaOH pellets to zinc granules and slowly heat. 5. Corrosion cannot be prevented by a. Oiling and Greasing b. Painting c. Adding antioxidants d. Galvanisation 6. This is not a correctly balanced equation is a. 2Al + Fe2O3 → Al2O3 +2Fe b. BaCl2 +ZnSO4 → ZnCl2 +BaSO4 c. Pb(NO3)2 (aq) + Fe2(SO4)3 (aq) → Fe(NO3)3 (aq) + PbSO4 (↓) d. 2H2S(g) +SO2(g) → 3S(s) +2H2O(l) 7. A balanced chemical equation does not provide this information. a. Mass of reactants and products. b. Physical states of reactants and products. c. Number of atoms of reactants and products. d. Shape and colour of reactants and products. 8. The reaction 2AgCl (s) ----> 2Ag(s) + Cl2(g) is used in (B) (A) a. Galvanisation b. Photography c. Electrolysis of water d. Copper plating 6

PRACTICE SHEET - 4 (PS-4) 9. In the reaction: CuSO4 (aq) + Zn (s) ------> Cu (s) + ZnSO4 (aq) a. Copper is oxidized and Zinc is reduced. b. Zinc is oxidized and Copper is reduced. c. Both Zinc and Copper are oxidized. d. Both Copper and Zinc are oxidized. 10. Somu has been collecting silver coins and copper coins as a hobby. One day he observed co loured coating on silver coins and on copper coins. Pick the correct colour coating for coins. a. Black coating on both silver coins and copper coins. b. Green coating on both silver coins and copper coins. c. Black coating on silver coins and green coating on copper coins. d. Green coating on silver coins and black coating on copper coins. II. Short Answer Questions. 1. Is potato chips packet filled with air? Yes or No. Support your answer and give detailed reason. 2. Draw a neat labelled diagram to show electrolysis of water. 3. Ria wanted to whitewash her room. She brought 5 kgs of Quicklime from the market and dissolved it in 15 litres of water. While mixing, in a bucket, she noticed that the water started boiling even when it was not be- ing heated. The bucket too became warm. Give reason for her observation. Write the corresponding chemical equation and the name of the product formed. III. Long Answer Questions. 1. Define Exothermic and Endothermic reactions. Give one example for each. Is respiration exothermic or endothermic? Write the balanced chemical equation for Respiration . 2. Define Decomposition reaction. Explain with balanced chemical equation the following types of reactions. i. Thermal decomposition ii. Photochemical decomposition iii. Electric decomposition 7

SELF-EVALUATION SHEET Marks: 20 Time: 30 Mins I.  Answer each of these in one or two words: (3 Marks) III.  Answer each of these in about 40-50 words. 1. Which type of reaction occurs when zinc reacts (6 Marks) with a solution of copper sulphate? 1. Translate the following statements into chemi- 2. Which compound is formed when sodium reacts cal equations and then balance them. with oxygen? a) Hydrogen gas reacts with nitrogen gas to form ammonia 3. Which type of reaction involves exchange of b) Sodium chloride reacts with aluminum sul- ions? phate to give sodium sulphate and ammonium chloride II.  Answer each of these in about 20-30 words. (6 Marks) c) Potassium reacts with water to give potassium 1. Arun kept 3 grams of silver chloride powder ex- hydroxide and hydrogen gas posed to the sunlight. What would he observe after sometime and why? 2. Why is respiration an exothermic reaction? 2. Compound ‘X’ is heated to produce compound Write a balanced chemical equation to support ‘Y’ and carbon dioxide. When compound ‘Y’ is your answer. treated with water, it forms calcium hydrox- ide. Identify compound X and Y. Compound X is treated with hydrochloric acid to release gas. This gas is collected and a burning splinter is in- troduced in the gas. Name the gas released and the observation made when a burning splinter is introduced. 3. Jaya heats a spoon of fine copper powder. What IV.  Answer this question in about 70 words. changes will she observe and why? (5 Marks) 1. i. How is oxidation reaction different from re- duction reaction? Explain with an example. ii. Explain why is corrosion and rancidity a type of oxidation reaction? 8

2. Acid, Bases and Salts Learning Outcomes At the end of this lesson students will be able to: • List out the common acids, bases and salts • Differentiate between acids, bases and salts. that are used in our daily life. • Describe the colour change observed in • Define pH and pH scale. indicators when it comes in contact with • Explain the preparation of commonly used acids and bases. salts. • Give examples of acids, bases and salts. • List out the uses of commonly used salts. • Explain chemical properties of acids and • Cite examples of different kinds of motion bases. seen in daily life. • Write balanced chemical equation for chemical reaction of acid, bases and salts. Concept Map Key Points • Acids are defined as the ones which produce greater than 7, then alkaline solution. If pH is less hydrogen ions in water. For example, sulphuric than 7, then the solution is acidic. acid, hydrochloric acid etc. • When an acid and base neutralize, salts are formed. Strong acid and strong base combines to • They give sour taste. Acids turn blue litmus to red. form neutral salt. • When acids and bases react with metals, gases • Living beings carry out their metabolic activities within an optimal pH range. are evolved. • Mixing concentrated acids or bases with water is a • Bases are the ones which produce hydroxide highly exothermic process. • Water of crystallization is the fixed number of ions in aqueous solutions. Bases which are water water molecules chemically attached to each soluble, are known as alkalis. They turn red formula unit of a salt in its crystalline form. litmus to blue. Keywords: Acid, bases, alkali, indicator, • They have a bitter taste. phenolphthalein, methyl orange, litmus, pH, pH scale, • They produce carbondioxide when reacted with water of crystallization carbonates. • Strength of an acid or base can be determined 9 using a pH scale. It is a scale to measure the hydrogen ion concentration in a solution. If pH is equal to 7, then the solution is neutral. If pH is

2. Acid, Bases and Salts Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SIMULATION/ SHEET VIDEO Indicators • Basic difference between PS-1 acids and bases with pH test by colour respect to taste PS-2 indicator • Use of indicators like PS-3 Acids react with phenolphthalein, methyl metal orange, litmus solution, PS-4 turmeric, onion and PS-5 Bases react with vanilla. Self-evaluation metal Sheet Chemical reactions of • Reaction of acids and Reaction of acids acids and bases bases with With bases » Carbonates pH test of » Bicarbonates » Oxide different solutions » Metals Removing water of crystallization • Neutralization reaction • Electrical conductivity of acids and bases • pH scale • pH value of some commonly used acids and bases • Importance of pH in daily life - pH • Acid rain » pH variation in soil » pH in our digestive system » Tooth decay » Chemical warfare by plants and animals Preparation and uses of • Sodium chloride commonly used salts • Bleaching powder • Sodium carbonate • Sodium bicarbonate • Plaster of Paris Worksheet for \"Acids, Bases and Salts\" Evaluation with self- check or Peer check* 10

PRACTICE SHEET - 1 (PS-1) I. Complete the table. Colour change in acid Colour change in base Indicator Phenolphthalein Methyl orange Turmeric Blue litmus solution Red litmus solution II. Find the odd one out. 1. Lemon juice, vinegar, baking soda, curd 2. Phenolphthalein, methyl orange, litmus solution, turmeric III. Answer each of these questions. 1. How would you differentiate between an acid and an alkali based on its taste? 2. What is the difference between a base and an alkali? 3. What are olfactory indicators? Give any two examples. PRACTICE SHEET - 2 (PS-2) I.  Write the products of each of these reactions. 1. Sodium carbonate + hydrochloric acid → 2. Sodium hydroxide + hydrochloric acid → 3. Calcium oxide + hydrochloric acid → 4. Zinc + hydrochloric acid → 5. Zinc + sodium hydroxide → II.  How would you test the presence of these gases? 1. Hydrogen. 2. Carbon dioxide III.  Answer these questions. 1. What are the different forms of calcium carbonate? 2. What happens when excess of carbon dioxide is passed through the lime water and why? 3. Which types of ions are liberated by acids and bases on dissociation? 4. What is dilution? 5. What happens when an aqueous solution of sodium hydroxide is made? Explain with the help of chemical equation. 6. Dry acids do not change the colour of blue litmus paper. Why? 11

PRACTICE SHEET - 3 (PS-3) I.  Fill in the blanks. 1. The ‘p’ in pH stands for ____. 2. The pH of neutral solution is _____. 3. The tooth enamel is made up of _____. 4. Stinging hair of nettle leaves inject _____ causing burning pain. 5. The acid present in tomato is ___. II.  Answer these questions. 1. What is acid rain? 2. How does a dilute solution of baking soda help to gain relief from acidity? 3. How does toothpaste help to prevent tooth decay? 4. A farmer wants to treat the soil in his field with calcium oxide. Why do you think farmer wants to do so? III. Place these items on the pH scale by considering their pH value. Blood, milk of magnesia, water, sodium hydroxide, lemon juice, gastric juice. PRACTICE SHEET - 4 (PS-4) I.  Write a balanced chemical equation to show the preparation of these compounds. 1. Sodium hydroxide 2. Baking soda 3. Bleaching powder II.  Answer each of these questions. 1. What is chlor alkali process? 2. Write any three uses of bleaching powder. 3. What is the difference between washing soda and sodium carbonate? 4. What is water of crystallisation? 5. How can you make gypsum out of plaster of Paris? 6. Write any five uses of chlorine. 7. What is the purpose of adding tartaric acid in baking powder? 12

PRACTICE SHEET - 5 (PS-5) 1. Electric current can flow in solution containing a. Acid and base b. Only acid c. Only base d. Acid, Base and Salt 2. The pH of a neutral solution is a. 1 b. 6 c. 7 d. 10 3. This salt is used in soda acid extinguisher a. CO2 b.NaHCO3 c. Na2CO3 d. NaCl 4. Hydrogen ions cannot exist alone. They combine with water molecule to form a. Dihydrogen ions b. Hydronium ions c. Hydride ions d. Hydroxyl ions 5. The acid that gets completely ionized in water a. CH3COOH b. NaOH c. H2SO4 d. H2SO3 6. Given below are the acidic solutions with their pH value. Pick the most acidic solution. a. Beer (pH = 4.2) b. Tomato juice (pH = 4.4) c. Coffee (pH= 4.8) d. Lemon juice (pH= 2.3) 7. When electricity is passed through Brine, a. NaOH and H2O are formed b. NaCl and H2O are formed c. NaOH and H2 are formed d. NaCl and H2 are formed 8. The chemical used for disinfecting drinking water to make it free of germs. a. CaCO3 b. Ca(OH)2 c. CaOCl2 d. CaO 13

PRACTICE SHEET - 5 (PS-5) 9. The pH value of a solution is 3. When its pH changes to 5, then H+ ion concentration a. Decreases three times b. Increases three times c. Decreases 100 times d. Increases 100 times 10. Baking powder contains sodium hydrogen carbonate and a. Calcium chloride b. Acetic acid c. Tartaric acid d. Sodium carbonate II. Short Answer Questions. 1. Write two similarities and two differences between Acids and Bases. 2. When a metal is treated with dil. H2SO4, a gas ‘X’ is evolved. It is collected by the method ‘Y’. Answer the following. i. Name the gas X. ii. Name the method of collection Y. iii. Is the gas X soluble or insoluble in water? 3. Write the chemical name of common salt. Write it’s any three importance in chemical industry. III. Long Answer Questions. 1. Explain the concept of water of crystallization in the formation of Plaster of Paris from Gypsum. Add a note on the uses of Plaster of Paris. 2. Explain with the help of an activity, the reaction of metal carbonates and metal hydrogen carbonates with acids. Write chemical reactions when i) carbon dioxide is passed through lime water ii) excess carbon dioxide is passed through it. 14

SELF-EVALUATION SHEET Marks: 20 Time: 30 Mins I.  Answer each of these in one word. (3 Marks) III.  Answer each of these in about 40-50 words. 1. The type of ions liberated by bases. (6 Marks) 2. pH value of water. 1. Justify the following statements. a. While diluting, we should not add water to acid, instead acid must be added to water. 3. A salt used in soda-acid fire extinguisher. II. Answer each of these in about 20-30 words. b. We should apply baking soda on a sting bite instead of lime juice. (6 Marks) 1. What happens when excess of carbon dioxide is passed through lime water? Support your an- swer with a balanced chemical equation. c. Acetic acid is a weak acid compared to hydro- chloric acid. 2. Dry slaked lime reacts with compound ‘A’ to 2. Write any three uses of sodium carbonate in give compound ‘B’ and water. Compound A is day to-day life. used to disinfect swimming pools. Identify com- pound A and B and write the balanced chemical equation for this reaction. 3. Sheetal and Reema have connected an electric circuit in beaker A and B respectively. Sheetal adds few spoons of lemon juice while Reema adds few spoons of coconut oil to their respec- tive beakers. Which beaker will the bulb con- nected to the circuit glow and why? 15

SELF-EVALUATION SHEET Marks: 20 Time: 30 Mins IV.  Answer this question in about 70 words. (5 Marks) 1. Brine is solution of substance A in water. When electricity is passed through it, substance B, chlorine and hydrogen are obtained. a) Identify the substances A and B. b) Write two uses each of substances A and B. c) Write a balanced chemical equation to depict the above mentioned reaction. 16

3. Metals and Non-metals Learning Outcomes At the end of this lesson, students will be able to: • Explain the bonding in metals and non-metals • Distinguish between metals and non-metals and their compounds. based on their physical properties. • Explain the occurrence of the metals. • Explain the chemical properties of metals and • Explain the method for extracting various non-metals with the help of various chemical metals. reactions. • List out the factors that affect corrosion of • Arrange the metals in the order of reactivity metal. series. • List out the ways to prevent corrosion. • Explain chemical properties of acids and bases. Concept Map Metals and Non-metals PPhhyyssiiccaallproper- Chemical reactions Extraction Corrosion tipersoopfemrteiteaslsoafnd of metals and non- of metals mentoanl-smaentdals metals non-  Occurrence of metals  Appearance  Ductility  Extracting  Malleability metals of low  Sonority activity series  Conductivity of  Extracting electricity and metals of heat middle activity series  Extracting metals of high activity series  Refining metals Key Points • Elements can be classified as metals and • Metal + oxygen → metal oxide non-metals. • Metal + water → metal hydroxide • Metal + dilute acid → salt + H2 • Metals and non-metals can be differentiated • Metal A + salt solution of metal B → Salt solution based on their physical and chemical properties. They can be differentiated based on their physi- of A + Metal B cal properties as: • Non-metals do not displace hydrogen from di- Metals Non-metals lute acids. They react with hydrogen to form hy- drides.  Hard  Soft • Non-metals form oxides which are either acidic or neutral while metallic oxides are basic in na-  Malleable  Non-malleable ture • A list of common metals arranged in order of  Ductile  Non-ductile their decreasing reactivity is known as an activ- ity series.  Lustrous  Non-lustrous • Metals above hydrogen in the activity series can displace hydrogen from dilute acids.  Good conductor  Poor conductor • The extraction of metals from their ores and then of heat and elec- of heat and elec- refining them for use is known as metallurgy. tricity tricity 17

3. Metals and Non-metals ing, galvanising, chrome plating, anodising or making alloys. Alloying is a very good method of • An alloy is a homogeneous mixture of two or improving the properties of a metal, as we can get more metals, or a metal and a non-metal. a substance with desired properties by this method. KEY WORDS – Ductility, malleability, lustre, galvaniza- • In a reaction between a metal and a non-met- tion, thermit reaction, ore, mineral. al, metals attain this stability by donating elec- trons, while non-metals do so by accepting electrons. Thus when they both combine, ionic bond is formed by the transfer of electrons. • Most metals are found in the earth’s crust in a combined form, and we have to extract them into their pure form, as they are very useful to us. • Iron or other metal articles get corroded in the presence of air and water. The rusting of iron can be prevented by painting, oiling, greas- 18

3. Metals and Non-metals Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SIMULATION/ SHEET VIDEO Physical properties of • Appearance PS-1 metals and non-metals • Ductility Physical Property: Surface • Malleability PS-2 Physical Property: • Sonority Hardness • Conductivity of electricity PS -3 Physical and heat PS-4 Property: Malleability • Boiling and melting point PS-5 Physical Property: Heat Self-evaluation Chemical reactions of • Reaction of metal with Sheet Physical Property: metals and non-metals water, oxygen, acids. Electricity • Displacement reaction Physical Property: • Reactivity series Sonority • Bonding between metals Chemical Property: Air and non-metals Chemical Property: Water • Ionic bonding Chemical Property: Acid • Properties of ionic compounds Extraction of metals • Occurrence of metals • Enrichment of ores • Extracting metals of low activity series • Extracting metals of middle activity series • Extracting metals of high activity series • Calcination • Roasting • Refining metals Corrosion • Factors influencing corrosion • Corrosion of silver, iron and silver • Galvanization • Alloying • Alloys Worksheet for \"Metals and Non-Metals\" Evaluation with self- check or Peer check* 19

PRACTICE SHEET - 1 (PS-1) 1. Differentiate between metals and non-metalwith respect to these criteria – hardness, lustre, electrical conductivity, thermal conductivity, ductility and malleability. 2. Name the following – a) A metal that is in liquid state. b) A non-metal that is lustrous. c) An allotrope of carbon that is used in making jewellery. d) A non-metal that conducts electricity. PRACTICE SHEET - 2 (PS-2) I.  Write the products of each of these reactions. 1. Calcium + water 2. Sodium oxide + water 3. Aluminum + oxygen 4. Show the formation of ionic bond in sodium and chlorine II.  Answer each of these questions. 1. Write any four properties of ionic compounds. 2. Why is hydrogen gas not evolved when a metal reacts with nitric acid? 3. Why does calcium float when it is put in a beaker of water? 4. Zn, Mg, Fe and Al. Arrange these metals in the decreasing order of chemical reactivity. 5. Copper coin is kept immersed in silver nitrate solution for some time. What change will take place in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. III.  Give reason for the following. 1. Aluminum oxide is considered as an amphoteric oxide. 2. Ionic compounds conduct electricity in molten state. PRACTICE SHEET - 3 (PS-3) I. Fill in the blanks. 1. The element that is placed at the top of reactivity series is ____. 2. Cinnabar is an ore of _____. 3. The large amount of impurities such as soil, sand, etc present in the ores is called ____. 4. During electrolysis, metals are deposited at the _____. II. Answer these questions. 1. What is thermit reaction? 2. What is the difference between roasting and calcination? 3. How would you extract the metals of high reactivity series? Explain with an example. 4. How is copper metal extracted? Show balanced chemical equation. 5. Write the chemical reactions at cathode and anode for electrolysis of molten sodium chloride. 6. Name any three metals that are found in free state. 20

PRACTICE SHEET - 4 (PS-4) I. In what way is the rusting different in silver, copper and iron? II.  Define these terms. 1. Galvanisation 2. Alloying. III.  Refer to the diagram and answer the questions that follow. 1. In which test tube does the rusting occur and why? 2. What is use of calcium chloride in this experiment? 3. Which elements make up these alloys? 1. Bronze 2. Brass 3. Solder 21

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option. 1. The metal that can be cut easily with a knife. a. Mercury b. Lithium c. Graphite d. Gallium 2. Metal that can melt on the palm. a. Mercury b. Sodium c. Caesium d. Potassium 3. Copper when burnt gets coated with this black layer of stable compound. a. Cu2O b. CuO c. Cu2O3 d. CuO2 4. Hydrogen gas is not evolved when metal reacts with a. HCl b. HNO3 c. H2SO4 d. HCO3 5. This metal does not react with dilute HCl a. Aluminium b. Zinc c. Magnesium d. Copper 6. Aqua regia is mixture of a. 1 part of concentrated Hydrochloric acid and 3 parts of dilute Nitric acid. b. I part of concentrated Nitric acid and 3 parts of dilute Hydrochloric acid. c. 1 part of concentrated Hydrochloric acid and 3 parts of concentrated Nitric acid. d. I part of concentrated Nitric acid and 3 parts of concentrated Hydrochloric acid. 7. Ria was experimenting on different metals, to check reaction of metals with oxygen. She would find that a. Silver and iron do not react with oxygen. b. Copper and Iron do not react with oxygen. c. Gold and Silver do not react with oxygen. d. Gold and Platinum do not react with oxygen 8. The metal that cannot be found in free state a. Platinum b. Copper c. Zinc d. Sodium 22

PRACTICE SHEET - 5 (PS-5) 9. Alloying is a method of improving the properties of a metal by adding other metals or non-metal to it. Iden- tify the incorrect combination for an alloy. a. Stainless steel:Iron, Nickel, Chromium b. Brass: Copper and Iron c. Bronze: Copper and Tin d. Solder: Lead and Tin 10. Given are the systematic steps involved in metallurgy process. i. Refining of impure metal ii. Conversion of concentrated ore into metal oxide. iii. Concentration of ore. iv. Reduction of metal oxide to metal. a. i,ii,ii,iv b. ii,iii,iv,i c. iii, ii,iv,i d. iv,iii,ii,i II. Short Answer Questions. 1. Show the formation of ionic bond between magnesium and chlorine. 2. Hydrogen is not a metal but it is assigned a place in the reactivity series of metals.Explain. 3. A piece of Zinc metal when placed in mercuric chloride solution acquires a shiny silvery surface but when placed in a magnesium sulphate solution no change is observed. Explain. II. Long Answer Questions. 1. i) Write the electronic configuration and electron dot structure for : sodium (11) , Oxygen (8) , Chlorine (17), Magnesium (12) ii) Write the electronic configuration of any two noble gases. 2. Explain in detail with a diagram why and how the metals are refined. 23

SELF-EVALUATION SHEET Marks: 15 Time: 30 Mins I.  Answer each of these in one or two words. 2. Explain the following physical properties of the (3 Marks) ionic compounds - physical state, melting and boiling point and solubility. 1. Name two allotropes of carbon 2. Which metal is placed at the top of reactivity series? 3. Name the alloy that is made up of copper and zinc. II.  Answer each of these in about 20-30 words. (6 Marks) 1. How does magnesium react with hot water? 2. How does aluminum oxide behave as an IV. Answer these question in about 70 words. amphoteric oxides? Justify with the help of bal- (5 Marks) anced chemical equation. 1. Explain the extraction of zinc from zinc carbon- ate and Zinc sulphide with the help of balanced chemical equations. 3. What would you observe when iron nail is kept 2. The carbonate ores are changed into oxides by in the copper sulphate solution? Give reason for heating strongly in limited air. your observation. III.  Answer each of these in about 40-50 words. (6 Marks) 1. Justify the following statements. a. Metals of low reactivity series can be reduced by heating alone. b. Ionic compounds conduct electricity only in the molten state. c. Iodine is an exception to the non-metals. 24

4. Carbon and its Compounds Learning Outcomes At the end of this lesson, students will be able to: • Describe how nomenclature of carbon com- • List the carbon made compounds. pounds is done. • Explain different covalently bonded carbon com- • Explain the different chemical properties of car- pounds and its properties. bon compound. • Draw the structure of different carbon com- • Explain how combustion takes place in carbon pounds. compounds. • Represent the electron dot structure of different • Explain the different types of reactions in carbon carbon compounds. compounds. • Explain the characteristics of allotropes. • Describe the properties of important carbon • Explain the different chain, branch and ring struc- compounds like ethanol, ethanoic acid. ture of carbon atoms. • Explain the cleansing action of soap. Concept Map Carbon and its compounds Bonds in carbon Versatile nature of carbon Chemical properties of carbon compound Important carbon Satucraartebdonancodmunpsoautnudrated Combustion Compounds Oxidation Addition Substitution Key Points properties remain the same. Example: diamond and graphite. They are also known as • Carbon is available in elemental form as well as allotropes of the carbon. in the combined form. • Carbon and its compounds show wide range of properties known as versatility of carbon. • Most of the carbon compounds are poor • Carbon can form bonds with other atoms of conductors. Forces of attraction between these carbon, by giving rise to molecules. This property molecules are very strong. These compounds do is called catenation. It can form single, double or not give any free ions. triple bonds with neighbouring carbon atoms. • Carbon has a valence of four, it is capable of • Elements have the tendency to attain noble gas bonding with four other atoms of carbon and configuration by losing or gaining electrons. some monovalent molecules. It may be nitrogen, Carbon can lose 4 electrons to become cation and can gain 4 electrons to become anion. • Carbon may be available in different forms by varying its physical properties, but its chemical 25

4. Carbon and its Compounds hydrocarbons. • The stable saturated hydrocarbon reacts hydrogen, oxygen sulphur, chlorine etc. • Saturated and unsaturated hydrocarbons in the presence of sunlight or may be in the presence of some high pressurized are 2 different types of hydrocarbons. environment called substitutional reactions. • If valencies of all atoms are satisfied by a • The ethanol and ethanoic acids are most important products of carbon. The ethanol single bond such carbon compounds are is commonly called as alcohol. Alcohol is not called saturated hydrocarbons. Examples: only used for drinking purposes but also used methane, ethane etc. in medicines such as cough syrups, tonics • If the valencies are not satisfied with a single etc., Alcohol is used as a fuel and is always bond and carbon forms double or triple blended with petroleum products. bond with neighbouring atoms, then it is • Alcohol affects health and causes many called unsaturated hydrocarbons. Example problems like mental confusions, lack of ethylene. coordination, drowsiness etc. • While forming bonds with neighbouring • Ethanoic acid belongs to carboxylic group. atoms, carbon may form chains, branches These are weak acids. The different products and rings. of these carboxylic groups can be used for • The compounds with an identical molecular cooking, examples vinegar, ester etc. but different structural formula are called Keywords: Carbon compounds, covalent bond, structural isomers. Examples C4H10, C6H12. saturated, unsaturated, nomenclature, fuels. • In hydrocarbon, the hydrogen can be replaced by oxygen, halogens, nitrogen and sulphur. The contributing atom is known as heteroatom. These heteroatoms confer specific properties to the compound, regardless of the length and nature of the carbon chain and hence are called functional groups. Examples alcohol, aldehydes, ketone, carboxylic acids etc. • The same functional group substitutes for hydrogen in a carbon chain is called a homologous group. • In a homologous series, as the molecular mass increases, a gradation in physical properties is seen. As the molecular mass increases, melting and boiling properties also changes. • Since carbon and its compounds are vast in nature, because of its friendly nature, naming carbon compounds is very important to identify its group. To name carbon compounds certain rules should be followed. • In carbon compounds, chemical properties can be studied in different reactions like combustion, oxidation, addition and substitution reactions. • Carbon burns in the presence of oxygen to give carbon dioxide along with the release of heat and energy. After burning saturated carbons, it gives clean flame but unsaturated hydrocarbon gives yellow flame with lots of black smoke. • Carbon compounds easily oxidize on combustion. From this, alcohol can be converted to carboxylic acids. • Unsaturated hydrocarbon reacts in the presence of catalyst to give saturated 26

4. Carbon and its Compounds Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET PS-1 Bonding in carbon • Introduction PS-2 Versatile nature of carbon • Covalent bond Chemical properties of carbon • Catenation PS-3 Important carbon compound • Bonding properties • Saturated and unsaturated compounds PS-4 • Combustion PS-5 • Oxidation Self-evaluation Sheet • Addition reaction • Substitution reaction • Ethanol • Ethanoic acid • Soaps and detergents Worksheet for \"Carbon and its Compounds\" Evaluation with self- check or peer check* 27

PRACTICE SHEET - 1 (PS-1) 1. State whether the following statements are true or false: a. All living structures are carbon based. b. Acetic acid melting point is greater than chloroform. 2. Explain the nature of covalent bond using CH3Cl as an example. 3. Draw the electron dot structure for propane, H₂S. 4. Draw the electronic dot structure of ammonia and methane. 5. What is the significance of covalent bonds in shaping the properties of the material? PRACTICE SHEET - 2 (PS-2) I. Answer the following questions: 1. What is catenation? 2. What are saturated and unsaturated hydrocarbons? 3. State whether the following statements are true or false. a. Carbon has a valency of five. b. The compounds always try to attain the noble structure. 4. Write the structure for the following compounds. a. Ethane b. Propane c. Butane d. Pentane 5. Explain the structural isomers with an example. 6. Fill in the blanks: a. Saturated hydrocarbons are also called as__________. b. The unsaturated hydrocarbons containing one or two double bonds are called as___. c. The unsaturated hydrocarbons containing triple bonds are called as______. d. In hydrocarbon the substituting element which replaces the hydrogen is called as_______. 7. Why is carbon called as a friendly element? 8. Match the following: Functional group Formula of functional group 1. Alcohol A 2. Aldehyde B C 3. Ketone 4. carboxylic acid D –OH 9. What is a homologous series? 10. How does the molecular weight of the compounds affect the property of the hydrocarbons? 28

PRACTICE SHEET - 3 (PS-3) I. Answer the following questions: 1. What is the combustion reaction of hydrocarbon? Explain with the help of examples. 2. Explain the different types of flames generated during the burning of hydrocarbons. 3. Explain the oxidation reaction of alcohols. 4. Explain the addition reaction and substitution reaction of the carbon compound. 5. What are the different types of chemical reactions seen in carbon compounds? PRACTICE SHEET - 4 (PS-4) I. Answer the following questions: 1. Why are ethanol and ethanoic acids considered as important carbon compounds? 2. Explain the reaction of ethyl alcohol with sodium and sulphuric acid. 3. State whether the following statements are true or false. a. Consumption of alcohol in small quantities will improve health. b. Consumption of small quantity of pure ethanol (absolute alcohol) is lethal. c. Ethanoic acid reacts with absolute ethanol in the presence of an acid catalyst to give an ester. d. The reaction which is used to make soaps is called saponification. e. Alcohol can be used as fuel. f. Methanol can be used for drinking purposes instead of ethanol. g. Ethanoic acid reacts with a base such as sodium hydroxide to give a salt. 4. How does alcohol affect living beings? 5. Explain the esterification reaction. 6. How is cleansing done by using soaps? 7. Why does washing of clothes becomes difficult in hard water? 29

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option. 1. The valency of carbon is a. 2 b. 4 c. 6 d. 8 2. If the functional group attached to the parent carbon chain is , then the resulting compound is a. Aldehyde b. Alcohol c. Ketone d. Carboxylic acid 3. The functional group that always occur at the terminal position of a carbon chain in a carboxylic acid is a. b. c. d. -OH 4. The functional group that always occur at the middle of a carbon chain is a. b. c. d. -OH 5. Identify the alkyne among the following. d. CH4 a. CH3CH2CH3 b. CH3CHCH2 c. CH2CH2 6. The phenomenon in which compounds have the same molecular formula but differ in physical and chemical properties is called a. Carbon dating b. Catenation c. Allotropy d. Isomerism 7. Advertisements of cooking oil insists on presence of unsaturated fatty acids. This is achieved by hydrogenation of vegetable oils using _____ as the catalyst. a. Sodium b. Magnesium c. Nickel d. Calcium 8. Generally , Unsaturated carbon compounds give a a. Blue flame b. Yellow sooty flame c. Clean flame d. Yellow non sooty flame 9. If we heat ethanol with potassium dichromate solution, the resulting product will be a. Ethene b. Ethanoic acid c. Ethane d. Ester 10. Identify the correct statement regarding allotropies of carbon. a. There are only two allotropies of carbon- Diamond and Graphite. b. Diamond is good conductor of electricity, whereas graphite is poor conductor of electricity. c. In graphite, there is one double bond, in the hexagonal arrangement. d. Diamonds cannot be synthesised artificially. II. Short Answer Questions. 1. Write the chemical reaction when ethanoic acid reacts with i) sodium carbonate ii) Sodium hydrogencarbonate. 2. Acetic acid was added to a solid ‘X’ kept in a test tube. A colourless and odourless gas was evolved. The gas turned lime water milky when passed through it. Predict the nature of the solid. 3. What is meant by denatured alcohol? Write its use. III. Long Answer Questions. 1. i) Explain with a suitable example and chemical reaction:Esterification and Saponification ii) Write the advantage and disadvantage on usage of detergents over soap. 2. Carbon is available in very small amount in nature. However it is of immense importance and outnumbers the compounds formed by all other elements. What makes this so unique? Elaborate. 30

SELF-EVALUATION SHEET Marks: 15 Time: 30 Mins I. Choose the most appropriate answer: II. Define the followings: (4 Marks) (2 Marks) 1. Structural isomers 2. Homologous series 1. Compounds always try to attain _____. a. Metal state 3. Saturated compounds 4. Heteroatom b. Noble gas configuration c. Individual elements d. Liquid state 2. Graphite and diamonds are called __________. a. smart materials b. allotropes c. costly materials d. none of the above 3. Write the chemical formulae and structure for III. Answer the following questions: the followings. (5 Marks) (4Marks) a. Butane 1. How are carbon(organic) compounds named? b. Benzene c. Propanol 2. Explain the formation of scum when hard water is treated with soap. d. Carboxylic acid e. Propanone 31

5. Periodic Classification of Elements Learning Outcomes • Explain the Mendeleev's periodic table. • Describe the limitation and advantages of Men- At the end of this lesson, students will be able to: • Describe how elements are classified based on deleev's model. • Describe how modern periodic table was made. the similar properties. • Write the new periodic table. • Explain the Döbereiner’s Triads. • Explain how modern periodic table is better than • Describe the Newlands’ law of octaves. • Explain the limitations of Döbereiner’s and New- other periodic tables. lands’ classification of models. Concept Map Classification of elements Döbereiner’ model Periodic tables Principle Newland ‘s Model Advantages Limitations Principle Advantages Limitations Mendeleev's model Key Points • John Newland an English scientist arranged the atoms based on their increasing atomic • The earliest attempt to classify the elements masses. He believed that every eighth element resulted in grouping the elements into metals has properties similar to that of the first. and non-metals. • It was known as Newlands law of octave. • Döbereiner’s German chemist tried to arrange • It was found that the Law of Octaves was the elements with similar properties. He made the group based on the increasing atomic applicable only up to calcium, as after calcium masses. The atomic mass of the middle every eighth element did not possess properties element was roughly the average of the atomic similar to that of the first. masses of other elements. • In order to fit the elements into the table, he adjusted two elements in the same slot, but put • He could identify the three triads from the some unwanted materials in the same note. But known element at that time. But this was not useful for the long-term. 32

5. Periodic Classification of Elements this theory worked for lighter elements only. • Dmitri Ivanovich Mendeleev, a Russian chemist studied the behavior of elements and classified the elements based on the properties of the metal. They are periodic functions of their atomic masses. • In this periodic table, sequence was inverted in a few cases so that similar metals can be grouped together. Even he guessed that there will be some metals they have not yet discovered. He could not assign correct position to hydrogen. Isotopes are not perfectly placed in the periodic table. • To overcome all the disadvantages of the previous tables in 1913, Henry Moseley designed new periodic table called the Modern periodic table. • Modern periodic table is based on the principle that “Properties of elements are a periodic function of their atomic number”. • In modern periodic table there are 18 vertical columns known as groups and 7 horizontal rows known as periods. Groups in the periodic table signify an identical outer shell electronic configuration. Each period marks a new electronic shell getting filled. • Atomic size increases down the group. Metallic character decreases across a period and increases across a period and increases down a group. • One zig-zag line separates the metals from the nonmetals. Non-metals are found on the right hand side of the periodic table. Keywords – metals, non-metals, elements, periodic table. 33

5. Periodic Classification of Elements Work Plan CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET PS-1 Early classification of Elements • Introduction • Dobereiner’s model PS-2 • John Newland model PS-3 Dmitri Ivanovich Mendeleev • Concept behind the model PS-4 Model • Scope of the model Self-evaluation Sheet • Advantages New periodic Table • Limitations • Concepts behind the table • Scope of the model • Arrangement of the elements • Advantages compared to the previous model Worksheet for \" Periodic Classification of Elements\" Evaluation with self- check or Peer check* 34

PRACTICE SHEET - 1 (PS-1) 1. State whether the following statements are true or false. a. Grouping of metals and non-metals was necessary. b. Triads are arranged based on the atomic masses. c. Newland’s law of octave worked only for lighter metals. 2. Explain how metals were arranged in Dobereiner’s model. 3. Why was Dobereiner’s model not useful? 4. Fill in the blanks. a. According to triads, the atomic mass of Br is 79 which is roughly the average of ________. b. Newland’s law of octaves based on the increasing ________. 5. Explain the Newlands law of Octaves. 6. What are the limitations of the Newland’s octave? PRACTICE SHEET - 2 (PS-2) 1. State whether the following statements are true or false. a. In Mendeleev's table only 63 elements are there. b. Mendeleev's table is based on the principle that the properties of elements are the periodic function of their atomic masses. c. Mendeleev belived that there are some elements yet to be discovered. 2. What are the limitations of Mendeleev's periodic table? 3. What are the achievements of Mendeleev's periodic table? 4. How did Mendeleev's classified the elements? 5. Fill in the blanks. a. The columns of the Mendeleev's s table are called as _____. b. According to Mendeleev's the properties of the elements are the periodic function of the ____________. c. The name of the preceding elements in the Mendeleev's s table is called as_______. PRACTICE SHEET - 3 (PS-3) 1. What is the basis of the modern periodic law? 2. State whether the following statements are true or false. a. The modern periodic table consists of 18 vertical columns known as groups. b. Groups in the periodic table signify an identical outer shell electronic configuration. c. The atomic size refers to the diameter of an atom. d. Maximum number of electrons that can be accommodated in a shell depends on the formula 2n3 e. As the effective nuclear charge acting on the valence shell electrons increases across a period, the tendency to lose electrons will decrease. 3. Define following terms w.r.t. modern periodic table. a. Atomic size b. Valency c. Groups d. Periods 4. Explain how elements are placed in the modern periodic table. 5. How does the electronic configuration of an atom relate to its positon in the modern periodic table? 6. Explain how metallic and non-metallic properties can be identified w.r.t modern periodic table. 35

PRACTICE SHEET - 4 (PS-4) I. Choose the correct option. 1. The element that exhibit maximum number of valence electrons a. Si b. Al c. Na d. P 2. A Modern periodic table a. has 18 horizontal rows known as periods. b. has 7 horizontal rows known as groups. c. has 18 vertical columns known as groups. d. has 7 vertical columns known as periods. 3. The element that is an essential constituent of all organic compounds belong to. a. group1 B.group 15 c. group16 d. group14 4. According to Mendeleev's periodic law, the elements were arranged in the order of a. Decreasing atomic masses b. Increasing atomic masses c. Increasing atomic number d. Decreasing atomic number 5. The Law of Octaves was applicable only upto a. Cobalt b. Potassium c. Calcium d. Phosphorus 6. Pick the correct characteristics of isotopes of an element i. same atomic number ii. same atomic mass iii. same physical properties iv. same chemical properties a. i, ii and iv b. i and iii c. i and iv d. ii and iii 7. Consider three elements A, B, C representing a Doberneir’s Triod. If the atomic mass of element A is 14 and that of element B is 46, then the atomic mass of element C will be a. 78 b. 72 c. 60 d. 28 8. An element ‘X’ forms an oxide X2O3. The element should be placed in which group of Mendeleev’s periodic table. a. Group II b. Group III c. GroupIV d. Group V 9. The element which can form an acidic oxide should be the one whose atomic number is a. 16 b. 12 c. 11 d. 19 36