AQA GCSE Chemistry: Teacher Pack by Collins

AQA GCSE (9â&#x20AC;&#x201C;1)

Chemistry Teacher Pack

Pam Large Lyn Nicholls Series editor: Ed Walsh

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06/06/16 3:16 PM

Contents Introduction

2.14 2.15

Graphene and fullerenes Nanoparticles, their properties and uses 2.16 Key concept: Sizes of particles and orders of magnitude 2.17 Maths skills: Visualise and represent 2D and 3D shapes When and how to use these pages: Check your progress, Worked example and End of chapter test

1 Atomic structure and the periodic table Introduction 1.1 Elements and compounds 1.2 Atoms, formulae and equations 1.3 Mixtures 1.4 Changing ideas about atoms 1.5 Modelling the atom 1.6 Relating charges and masses 1.7 Sub-atomic particles 1.8 Electronic structure 1.9 The periodic table 1.10 Developing the periodic table 1.11 Comparing metals and non-metals 1.12 Metals and non-metals 1.13 Key concept: The outer electrons 1.14 Exploring Group 0 1.15 Exploring Group 1 1.16 Exploring Group 7 1.17 Reaction trends and predicting reactions 1.18 Transition metals 1.19 Maths skills: Standard form and making estimates When and how to use these pages: Check your progress, Worked example and End of chapter test

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35

Collins GCSE Science

77 79 81

3 Chemical quantities and calculations Introduction 3.1 Key concept: Conservation of mass and balanced equations 3.2 Relative formula mass 3.3 Mass changes when gases are in reactions 3.4 Chemical measurements and uncertainty 3.5 Moles 3.6 Amounts of substances in equations 3.7 Using moles to balance equations 3.8 Concentration of solutions 3.9 Key concept: Percentage yield 3.10 Atom economy 3.11 Using concentrations of solutions 3.12 Amounts of substance in volumes of gases 3.13 Key concept: Amounts in chemistry 3.14 Maths skills: Change the subject of an equation When and how to use these pages: Check your progress, Worked example and End of chapter test

37 39 41

2 Structure, bonding and the properties of matter Introduction 2.1 Chemical bonds 2.2 Ionic bonding 2.3 Ionic compounds 2.4 Covalent bonding 2.5 Metallic bonding 2.6 Three states of matter 2.7 Properties of ionic compounds 2.8 Properties of small molecules 2.9 Polymer structures 2.10 Giant covalent structures 2.11 Properties of metals and alloys 2.12 Diamond 2.13 Graphite

73 75

45 47 49 51 53 55 57 59 61 63 65 67 69 71

85 87 89 91 93 95 97 99 101 103 105 107 109 111 113 115

4 Chemical changes Introduction 4.1 Metal oxides 4.2 Reactivity series 4.3 Extraction of metals 4.4 Oxidation and reduction in terms of electrons 4.5 Reaction of metals with acids 4.6 Neutralisation of acids and salt production

iii

119 121 123 125 127 129 131

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4.7 4.8

Soluble salts Required practical: Preparing a pure, dry sample of a soluble salt from an insoluble oxide or carbonate 4.9 pH and neutralisation 4.10 Required practical: Finding the reacting volumes of solutions of acid and alkali by titration 4.11 Strong and weak acids 4.12 The process of electrolysis 4.13 Electrolysis of molten ionic compounds 4.14 Using electrolysis to extract metals 4.15 Electrolysis of aqueous solutions 4.16 Required practical: Investigating what happens when aqueous solutions are electrolysed using inert electrodes 4.17 Key concept: Electron transfer, oxidation and reduction 4.18 Maths skills: Make order of magnitude calculations When and how to use these pages: Check your progress, Worked example and End of chapter test

133 135

6 The rate and extent of chemical change Introduction 6.1 Measuring rates 6.2 Key concept: Limiting reactants and molar masses 6.3 Calculating rates 6.4 Factors affecting rates 6.5 Required practical: Investigate how changes in concentration affect the rates of reactions by a method involving the production of a gas and a method involving a colour change 6.6 Factors increasing the rate 6.7 Collision theory 6.8 Catalysts 6.9 Reversible reactions and energy changes 6.10 Equilibrium 6.11 Changing concentration and equilibrium 6.12 Changing temperature and equilibrium 6.13 Changing pressure and equilibrium 6.14 Maths skills: Use the slope of a tangent as a measure of rate of change When and how to use these pages: Check your progress, Worked example and End of chapter test

137 139

141 143 145 147 149 151

153 155 157

5 Energy changes Introduction 5.1 Key concept: Endothermic and exothermic reactions 5.2 Required practical: Investigate the variables that affect temperature changes in reacting solutions such as, acid plus metals, acid plus carbonates, neutralisations, displacement of metals 5.3 Reaction profiles 5.4 Energy change of reactions 5.5 Cells and batteries 5.6 Fuel cells 5.7 Maths skills: Recognise and use expressions in decimal form When and how to use these pages: Check your progress, Worked example and End of chapter test

Collins GCSE Science

161 163 165

181 183 185 187 189 191

193 195 197 199 201 203 205 207 209

211

7 Hydrocarbons Introduction 7.1 Crude oil, hydrocarbons and alkanes 7.2 Fractional distillation and petrochemicals 7.3 Properties of hydrocarbons 7.4 Combustion 7.5 Cracking and alkenes 7.6 Structure and formulae of alkenes 7.7 Reactions of alkenes 7.8 Alcohols 7.9 Carboxylic acids 7.10 Addition polymerisation 7.11 Condensation polymerisation 7.12 Amino acids 7.13 DNA and other naturally occurring polymers

167 169 171 173 175 177

215 217 219 221 223 225 227 229 231 233 235 237 239 241

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7.14

Key concept: Intermolecular forces 7.15 Maths skills: Visualise and represent 3D models When and how to use these pages: Check your progress, Worked example and End of chapter test

243 245

When and how to use these pages: Check your progress, Worked example and End of chapter test

247

10 Sustainable development Introduction 10.1 Key concept: Using the Earth’s resources and sustainable development 10.2 Potable water 10.3 Required practical: Analysis and purification of water samples from different sources, including pH, dissolved solids and distillation 10.4 Waste water treatment 10.5 Alternative methods of metal extraction 10.6 Life cycle assessment and recycling 10.7 Ways of reducing the use of resources 10.8 Corrosion and its prevention 10.9 Alloys as useful materials 10.10 Ceramics, polymers and composites 10.11 Haber process 10.12 Production and use of NPK fertilisers 10.13 Maths skills: Translate information between graphical and numerical form When and how to use these pages: Check your progress, Worked example and End of chapter test

8 Chemical analysis Introduction 8.1 Key concept: Pure substances 8.2 Formulations 8.3 Chromatography 8.4 Required practical: Investigate how paper chromatography can be used in forensic science to identify an ink mixture used in a forgery 8.5 Test for gases 8.6 Flame tests 8.7 Metal hydroxides 8.8 Tests for anions 8.9 Required practical: Use chemical tests to identify the ions in unknown single ionic compounds 8.10 Instrumental methods 8.11 Flame emission spectroscopy 8.12 Maths skills: Use an appropriate number of significant figures When and how to use these pages: Check your progress, Worked example and End of chapter test

251 253 255 257 259

261 263 265 267 269

271 273 275 277

9 The atmosphere Introduction 9.1 Proportions of gases in the atmosphere 9.2 The Earth’s early atmosphere 9.3 How oxygen increased 9.4 How carbon dioxide decreased 9.5 Key concept: Greenhouse gases 9.6 Human activities 9.7 Global climate change 9.8 Carbon footprint and its reduction 9.9 Limitations on carbon footprint reduction 9.10 Atmospheric pollutants from fuels 9.11 Properties and effects of atmospheric pollutants 9.12 Maths skills: Use ratios, fractions and percentages

Collins GCSE Science

281 283

Student Book answers Programme of study matching chart Using the student book to teach Combined Science: Trilogy

285 287 289 291 293 295 297 299

307

311 313

315 317

319 321 323 325 327 329 331 333 335 337

339

343 386 410

301 303 305

Chapter 1: Atomic structure and the periodic table

Atomic structure and the periodic table: Introduction When and how to use these pages This unit builds on the idea that the atom is the building block of matter – it underpins a lot of work in chemistry.

Overview of the unit The students will learn about the structure of atoms and use a range of different models to describe both the atoms themselves and the physical and chemical properties of the elements and compounds they form. They will also explore how atomic models developed as new data became available and how the periodic table was constructed. In the process they will learn how testing predictions can support or refute new scientific ideas. Students will carry out experiments, describe practical procedures, select techniques for a particular purpose and explain their choices. They will also make and record observations, describe patterns in data and use data to make predictions. The unit offers a number of opportunities for students to use mathematics. They visualise and represent twodimensional (2D) and 3D forms, use ratios to write simple formulae, substitute numerical values into chemical equations to balance them, use prefixes and powers of ten to describe the sizes of atoms and their components, translate data between graphical and numerical form, plot variables against each other to describe trends and relationships; and interpolate and extrapolate graphs to make predictions.

Obstacles to learning Atoms and their sizes are abstract concepts and are hard to visualise. The use of models and analogies may help some students to recognise that atoms are very small, that most of their volume is made up of empty space and that they bond together to make 3D structures. The use of physical models and diagrams will also help students to classify substances as elements, compounds and mixtures, their particles as atoms, ions or molecules, and their structures as atomic, molecular or crystalline. Particle pictures and physical models will also help students who struggle to use ratios to determine formulae and to balance chemical equations.

Practicals in this unit In this unit students will do the following practical work:

 Observe a demonstration to make a compound from two elements.  Separate a mixture of copper powder and sodium chloride using filtration and evaporation.  Burn strips of magnesium ribbon and observe the traces of magnesium oxide produced.  Make space-filling models of the molecules in a selection of elements and compounds.  Model the electron arrangements in atoms.  Model the arrangement of elements in the periodic table.  Test a range of metal and non-metal oxides in water with universal indicator solution.  Model the changes in electron arrangements when atoms react to form ions.

Collins GCSE Science

Chapter 1: Atomic structure and the periodic table

Lesson title

Overarching objectives

Elements and compounds

Use chemical symbols and formulae to describe elements and compounds.

Atoms, formulae and equations

Know that the atoms in an element are all the same and use symbols and formulae to represent elements and compounds and simple chemical reactions.

Mixtures

Understand how different techniques are used to separate mixtures.

Changing ideas about atoms

Describe how ideas about atoms changed as new evidence became available.

Modelling the atom

Model atoms as positive nuclei surrounded by negative electrons.

Relating charges and masses

Describe the similarities and differences between protons, neutrons and electrons.

Sub-atomic particles

Use atomic numbers and mass numbers to determine the numbers of sub-atomic particles in atoms.

Electronic structure

Describe the arrangement of electrons in shells or energy levels.

The periodic table

Describe the link between electronic structure and an elementâ&#x20AC;&#x2122;s position in the periodic table.

Developing the periodic table

Describe how Mendeleev developed the periodic table.

Comparing metals and nonmetals

Describe the physical and chemical differences between metals and nonmetals.

Metals and non-metals

Distinguish metals from non-metals using their position in the periodic table and ability to form positive ions.

Key concept: The outer electrons

Understand how outer electrons can be transferred or shared.

Exploring Group 0

Explain their lack of reactivity and trends in their physical properties.

Exploring Group 1

Describe their high reactivity and trends in their chemical properties.

Exploring Group 7

Describe their high reactivity and trends in their physical and chemical properties.

Reaction trends and prediction reactions

Explain trends in reactivity in Groups 1 and 7 and changes across a period.

Transition metals

Describe similarities and differences between transition metals and contrast them with those of Group 1 elements.

Maths skills: Standard form and making estimates

Recognise and use standard form in calculations.

Collins GCSE Science

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Chapter 1: Atomic structure and the periodic table

Lesson 1: Elements and compounds Lesson overview AQA Specification reference AQA 4.1.1.1

Learning objectives  Identify symbols of elements from the periodic table.  Recognise the properties of elements and compounds.  Identify the elements in a compound. Learning outcomes  Recognise that the periodic table contains all known elements and be able to use names and symbols of the first twenty elements. [O1]

 Describe how a compound such as iron sulfide is made from elements in a chemical reaction. [O2]  Distinguish between formulae for elements and compounds and name the elements in a compound. [O3] Skills development  WS 1.2 Use a variety of models such as representational, spatial, descriptive, computational and mathematical to solve problems, make predictions and to develop scientific explanations and understanding of familiar and unfamiliar facts.

 WS 3.5 Interpret observations and other data (presented in verbal, diagrammatic, graphical, symbolic or numerical form), including identifying patterns and trends, making inferences and drawing conclusions.

 WS 4.1 Use scientific vocabulary, terminology and definitions. Resources needed: Student copies of the periodic table, class poster of the periodic table, circles of coloured card or plasticine to model atoms (optional), Worksheet 1.1.1, Worksheet 1.1.2, Practical sheet 1.1, Technician notes 1.1.

Digital resources Internet access is required for the ‘Extend’ section Key vocabulary balanced, compound, element, equation, symbol

Teaching and learning Engage  Display 12 kg of barbecue charcoal and identify it as the average mass of the element carbon in a 15-yearold girl. Introduce the idea that we get carbon into our bodies by eating. [O1] Ask for examples of foods that contain carbon and discuss the fact that that the element carbon cannot be seen because it is chemically joined with other elements in compounds. Bread can be toasted to make the compounds (carbohydrates and proteins) in it react and leave a layer of carbon on its surface. [O1] Remind students that our bodies excrete some carbon when we breathe out. We cannot see the particles of carbon because it is now combined with oxygen as carbon dioxide. Establish that carbon is an element and carbon dioxide is a compound.

Challenge and develop Low demand

 Explain that carbon is one of 92 naturally occurring elements and there are 26 more that are made synthetically. Show students how we organise these elements in the periodic table. They can practice finding symbols for named elements to familiarise themselves with the table. Explain that all the compounds in the known Universe are made from these elements. Students can answer questions 1 and 2 on Worksheet 1.1.1. [O1]

Collins GCSE Science

Chapter 1: Atomic structure and the periodic table

Standard demand

 Use Practical sheet 1.1 to demonstrate the reaction between iron and sulfur to make iron sulfide. This should be carried out in a fume cupboard. [O2]

Explain Standard demand

 Students can answer the questions on the practical sheet. Check their answers and establish that the elements iron and sulfur have combined in a chemical reaction to make the compound iron sulfide. The reaction can be modelled using circles of coloured card or different coloured balls of plasticine to show that one iron atom combines with one sulfur atom. Note that because iron sulfide has an ionic structure, this model has its limitations, but is useful to show the 1:1 ratio of iron sulfide and the idea of elements combining in fixed proportions. [O2]

 Students can read the section ‘Elements and compounds’ in Section 1.1 in the Student Book and answer question 3 on Worksheet 1.1.1. [O2] High demand

 Explain that we use the chemical symbols for elements to write formulae for compounds. Students can answer the questions on Worksheet 1.1.2 to practise identifying the elements present in different compounds and how they are named. [O3]

Consolidate and apply  Students can discuss what is meant by the statement ‘the same compound always has the same formula, no matter where and how it is made or found’. [O3]

 Students can answer questions 1 to 7 in Section 1.1 of the Student Book. [O1, O2, O3]. Extend Ask students able to progress further to research the discovery of the elements with atomic numbers 113, 115, 117 and 118 and why this discovery has completed the seventh row of the periodic table. They will need internet access. Students can present their finding to the class. [O1]

Plenary suggestions Students need two strips of paper. They can write a question on today’s lesson on one strip and the answer on the other. In groups of five or six, the questions and answers are shuffled and redistributed so that each student has a question and an answer. One student asks their question and the student with the correct answer responds and asks their question in turn.

Answers to Worksheet 1.1.1 1. a) C; b) O; c) Ca; d) Cu; e) Na; f) H; g) K; h) Fe; 2. a) S is the symbol for sulfur; b) e.g. sodium Na; lead Pb; potassium K; iron Fe; 3. (a) Sodium; chlorine; b) Sodium chloride; c) Na and Cl; d) Energy is given out; a new substance is made; e) A white powder is produced; f) Another chemical reaction

Answers to Worksheet 1.1.2 1. Magnesium and oxygen, copper and sulfur, sodium and bromine, potassium and iodine, lithium and oxygen, aluminium and chlorine, copper and nitrogen, copper and sulfur; 2. a) Magnesium sulfide, magnesium and sulfur; b) Iron sulfide, iron and sulfur; c) Copper oxide, copper and oxygen; d) Potassium iodide, potassium and iodine; e) Sodium chloride, sodium and chlorine; f) Calcium oxide, calcium and oxygen; g) Lithium bromide, lithium and bromine; h) Magnesium oxide, magnesium and oxygen

Answers to Practical sheet 1.1 1. Fe, S; 2. Use a magnet to attract the iron particles; .3. Heat and light given out; 4. Mixture is grey/yellow powder; iron sulfide is black and solid; 5. Iron sulfide; 6. No

Collins GCSE Science

Chapter 1: Atomic structure and the periodic table

Lesson 2: Atoms, formulae and equations Lesson overview AQA Specification reference AQA 4.1.1.1

Learning objectives  Learn the symbols of the first 20 elements in the periodic table.  Use symbols to describe elements and compounds.  Use formulae to write equations. Learning outcomes  Recognise elements and compounds of the first 20 elements from their formulae. [O1]  Write formulae correctly using elements from Groups 1, 2, 6 and 7. [O2]  Write equations for simple reactions. [O3] Skills development  WS 1.2 Use models in explanations.  WS 2.4 Carry out experiments appropriately.  WS 4.1 Use scientific terminology. Maths focus Use ratios Resources needed Equipment as listed in the Technician’s notes; a periodic table for each pupil; a large wallmounted periodic table; a printed copy of each slide in Presentation 1.2 displayed on a notice board visible to the students; Worksheets 1.2.1, 1.2.2 and 1.2.3; Practical sheet 1.2; Technician’s notes 1.2 Digital resources Presentation 1.2 ‘Name that compound’ Key vocabulary compound, element, molecule

Teaching and learning Engage  Display unlabelled samples of magnesium powder and calcium oxide. Ask students to deduce which is an element and which is a compound. [O1, O2 and O3]

 Present the formula of each sample and discuss how symbols can make it easier to identify elements and compounds. Make sure every student has a periodic table. [O1, O2 and O3]

Challenge and develop  Low demand: Give out Practical sheet 1.2.1. Students work in pairs to burn a sample of magnesium ribbon and answer the questions. [O1 and O2]

 Standard and high demand: Challenge students to burn magnesium and describe the product formed using words and symbols. CARE! Students must hold the magnesium with tongs at arm’s length and must not look directly at the flame. [O1 and O2]

 Low demand: Ask students to read ‘Elements and compounds’ from Section 1.2 of the Student Book and complete questions 1 and 2. [O1]

 All students: Introduce the idea that each compound has a set formula and that this contains the symbols of the elements that reacted to make it. Students complete the quiz on Presentation 1.2 to practice identifying symbols. [O1 and O2]

 Standard and high demand: Challenge groups to identify patterns in the formulae of the compounds in Presentation 1.2 and ask each group in turn to offer one new point until every group ‘passes’. Collins GCSE Science

Chapter 1: Atomic structure and the periodic table

Explain  Low demand: Read ‘Formulae’ from Section 1.2 of the Student Book and then complete questions 3 and 4, and those in part 1 of Worksheet 1.2.1. [O1 and O2]

 Standard and high demand: Read ‘Formulae’ from Section 1.2 of the Student Book and then complete questions 3 and 4, and those in part 1 of Worksheet 1.2.2. [O1 and O2]

Consolidate and apply  Low demand: Students construct the formulae and equations in Worksheets 1.2.1 and 1.2.2. [O2 and O3]  Standard and high demand: Students construct the formulas and equations in Worksheet 1.2.3. [O2 and O3] Extend Ask students able to progress further to devise a help sheet to support students who don’t know how to balance equations. [O3]

Plenary suggestion Ask students to write down three things they learned about writing equations. Then ask them to share their facts in groups and compile a master list, with the most important facts at the top.

Answers to Worksheet 1.2.1 a) CaO; b) CaCl2; c) NaF, d) BeS; e) BeF2; f) LiF; g) MgS; h) KCl; i) MgF2; j) Li2O; k) Na2O; l) Li2S

Answers to Worksheet 1.2.2 a) 2Ca + O2 → 2CaO; b) Ca + Cl2 → CaCl2; c) 2Na + F2 → 2NaF; d) Be + S → BeS; e) Be + F2 → BeF2; f) 2Li + F2 → 2LiF; g) Mg + S → MgS; h) 2K + Cl2 → 2KCl; i) Mg + F2 → MgF2; j) 4Li + O2 → 2Li2O; k) 4Na + O2 → 2Na2O; l) 2Li + S → Li2S

Answers to Worksheet 1.2.3 1 a) CaO; b) CaCl2; c) NaF; d) BeS; e) BeF2; f) LiF; g) MgS; h) KCl; i) MgF2; j) Li2O; k) Na2O; l) Li2S 2 a) 2Ca + O2 → 2CaO; b) Ca + Cl2 → CaCl2; c) 2Na + F2 → 2NaF; d) Be + S → BeS; e) Be + F2 → BeF2; f) 2Li + F2 → 2LiF; g) Mg + S → MgS; h) 2K + Cl2 → 2KCl; i) Mg + F2 → MgF2; j) 4Li + O2 → 2Li2O; k) 4Na + O2 → 2Na2O; l) 2Li + S → Li2S

Answers to Practical sheet 1.2 1. Any two differences; 2. Magnesium oxide; 3. A, 4. B, 5. D; 6. Magnesium + oxygen → magnesium oxide; 7. The oxygen atoms are bonded/joined together

Collins GCSE Science

When and how to use these pages: Check your progress, Worked example and End of chapter test Check your progress Check your progress is a summary of what students should know and be able to do when they have completed the chapter. Check your progress is organised in three columns to show how ideas and skills progress in sophistication. Students aiming for top grades need to have mastered all the skills and ideas articulated in the final column (shaded pink in the Student book). Check your progress can be used for individual or class revision using any combination of the suggestions below:   

 

Ask students to construct a mind map linking the points in Check your progress Work through Check your progress as a class and note the points that need further discussion Ask the students to tick the boxes on the Check your progress worksheet (Teacher Pack CD). Any points they have not been confident to tick they should revisit in the Student Book. Ask students to do further research on the different points listed in Check your progress Students work in pairs and ask each other what points they think they can do and why they think they can do those, and not others

Worked example The worked example talks students through a series of exam-style questions. Sample student answers are provided, which are annotated to show how they could be improved. 

Give students the Worked example worksheet (Teacher Pack CD). The annotation boxes on this are blank. Ask students to discuss and write their own improvements before reviewing the annotated Worked example in the Student Book. This can be done as an individual, group or class activity.

End of chapter test The End of chapter test gives students the opportunity to practice answering the different types of questions that they will encounter in their final exams. You can use the Marking grid provided in this Teacher Pack or on the CD Rom to analyse results. This shows the Assessment Objective for each question, so you can review trends and see individual student and class performance in answering questions for the different Assessment Objectives and to highlight areas for improvement.    

Questions could be used as a test once you have completed the chapter Questions could be worked through as part of a revision lesson Ask Students to mark each other’s work and then talk through the mark scheme provided As a class, make a list of questions that most students did not get right. Work through these as a class.

Collins GCSE Science

Student Name

Marking Grid for End of Chapter 1 Test

Getting Started [Foundation Tier]

Q. 1 1 mark Q. 2 1 mark Q. 3 2 marks Q. 4 1 mark Q. 5 1 mark Q. 6 2 marks Q. 7 2 marks Q. 8 1 mark

Going Further [Foundation and Higher Tiers]

Q. 9 1 mark Q. 10 2 marks Q. 11 4 marks Q. 12 2 marks Q. 13 1 mark

More Challenging [Higher Tier]

Q. 14 1 mark Q. 15 2 marks Q. 16 6 marks Most demanding [Higher Tier]

Q. 17 2 marks Q. 18 4 marks Q. 19 4 marks

Total marks Percentage

Chemistry

Check your progress You should be able to:

■

name compounds from their formula

■

➞ ■ ■ ■

■

■ ■ ■ ■

■ ■

describe how to separate mixtures of elements and compounds explain that early models of the atom did not have shells with electrons draw a diagram of a small nucleus containing protons and neutrons with orbiting electrons at a distance describe how Mendeleev was able to leave spaces for elements that had not yet been discovered

■

➞ ■

➞

describe the pattern of the electrons in shells for the first 20 elements

➞

describe a number of physical properties of metals and non-metals

➞

explain that non-metals are on the right-hand side of the periodic table describe the unreactivity of the noble gases

■

➞ ■

➞

predict the reactions with water of Group 1 elements lower than potassium

➞

recall the colours of the halogens and the order of reactivity of chlorine, bromine and iodine

➞

explain that a stable outer shell of electrons makes noble gases unreactive

➞

explain that transition metals have higher melting points and are stronger and harder than Group 1 metals

➞

■ ■

recall the names of the first 20 elements in the periodic table and the elements in Groups 1 and 7 use word equations to describe chemical reactions explain that early models of atoms developed as new evidence became available calculate the numbers of sub-atomic particles in ions and isotopes given the atomic and mass numbers explain why the modern periodic table has the elements in order of atomic number explain how the electronic arrangement of atoms follows a pattern up to the atomic number 20 explain that atoms of metals have 1, 2 or 3 electrons in their outer shell

use symbol equations to describe chemical reactions

■

use balanced equations to describe reactions

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explain why the scattering experiment led to a change in the atomic model

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complete data tables showing the atomic numbers, mass numbers and numbers of subatomic particles from symbols.

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explain how Mendeleev was able to make predictions of as yet undiscovered elements such as eka-silicon

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explain how the electronic arrangement of transition metal atoms put them into a period

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explain that non-metals need to gain or share electrons during reactions and that metals need to lose electrons during reactions.

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predict the relative reactivity across the periods and give reasons

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explain the trend down Group 0 of increasing boiling point in terms of atomic mass

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explain the trend down the group of increasing reactivity by electron structure

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predict displacement reaction outcomes of halogens other than chlorine, bromine and iodine.

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explain the trend of increasing reactivity in terms of electron structure

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explain that transition metals form ions of different charges and are useful as catalysts

➞

➞ ➞

➞

explain that non-metals have 4, 5 ,6, 7 or 8 electrons in their outer shell

➞

explain the trend down Group 0 of increasing boiling point

➞

predict and explain the relative reactivity down the groups

➞

describe the order of reactivity and explain the displacement of halogens

■

➞

predict the properties of ‘unknown’ elements from their position in the group

➞

explain that transition metals are less reactive than Group 1 metals and form coloured solutions

➞

Worked example Sam and Alex are researching some properties of Group 1 metals. 1

Shade the section of the periodic table where the Group 1 metals are found.

This is incorrect. The first column needs to be shaded.

H H

1 1

hydrogen

lithium

23 11

beryllium

Na 12 Mg

sodium magnesium

40 20

45 21

48 22

potassium calcium scandium titanium

85 37

rubidium strontium

133 55

caesium

223 87

francium

137 56

barium

89 39

yttrium

139 57

227

radium

91 40

zirconium

178 72

lanthanum hafnium

226

261 106

actinium rutherfordium

The two metals they are researching are sodium and potassium. 2

Write down two properties that these metals have.

They are shiny when cut

The first property is correct. However, sodium and potassium float on water so have a density less than water. The student may be confusing group 1 metals with transition metals, which have high density.

They have a very high density

Sam and Alex find out that sodium and potassium react with water. They find that sodium reacts with water to make sodium hydroxide and that hydrogen is given off. 3

Write a word equation for the reaction

sodium + water → sodium hydroxide

Sam says that potassium reacts more vigorously than sodium but Alex says that they are in the same group so they react the same. 4

The reactants are correct but hydrogen needs to be written as a product on the right hand side.

a Explain why Sam is correct about the trend.

The lower down the group the better they react b Explain why Sam is correct using ideas about the structure of atoms.

The bigger the atom the quicker the reaction

This answer could be expressed more clearly by substituting the word ‘better’ with ‘more vigorously’.

This answer needs more detail. The further away the outer electron is from the nucleus the more easily it is ‘lost’, as the pull by the positive nucleus on the negative electron is less.