Year 8 Science Home Learning PackThis Pack is designed for 10 hours worth of learning.

What does this mean? You will be revising the topics that you have been taught so far. These include:

1. Health and Lifestyle2. Periodic table3. Electricity & Magnetism

For each topic, use the resources in this pack.

What do I need to know for these units? See the knowledge organisers, If you have access to the textbook on Kerboodle, use that too.

Which words do I need to understand and use? Task: Go through all the knowledge organisers, pick out the keywords. Add these to your glossary with a definition and use each one in a sentence. You might be able to use several words in one sentence.)

What do I need to know about these topics?Once you have completed your learning, complete the questions included in this pack in worksheets

How can I show that I understand this really well?Complete the questions and ‘Extended response activity’. Check your answers using the guidance provided.You won’t be able to conduct the practicals but this sets the context for you to understand and answer the questions that follow.All answers are provided to the task set.

Send your completed work back to your teacher for further feedback.

constipationit moving through the gut. Stops Provides bulk to the food to keepFibre

cells and body fluidsNeeded in allWater

and vegetables are a good source. us healthy, Fruits Only need tiny amounts but are essential for keepingVitamins and Minerals

Turns purple, food contains protein3)solution

Add a few drops of sodium hydroxide 2)solution to your food solution1) Add a few drops of copper sulfate

proteinimmune system mainly made of

Muscles, organs and for growth.Repair body tissue and make new cells Proteins

contains lipidstranslucent it 2) If the paper has gone

Rub some food on filter paper1)

organs from damage2) protect our energy, 2)Keep us warm

and Oils. 1) Provide with a store of FatsLipids

Turns blue/black, contains starch2)Add a few drops of iodine solution1)

Starchred, contains sugar-3) If turns orange

Heat test tube in a water bath2) Add a few drops of Benedicts solution1)

Sugar

the body so energy is released slowly.and bread, these are broken down by Found in starchy foods such as pasta

they provide a quick source of energy.and fruit where foods such as sugar

Main source of energy found in sugary Carbohydrates

Nutrients

are stored in the rectum until leaving the body through the anusFaecesRectum and Anus

back into the bodyater passesWFood that cannot be digested.Large Intestine

small molecules are absorbed into the blood streamWhereSmall Intestine

Food mixed with digestive juices and acid. It churns to mix food.Stomach

from the mouth to the stomachTubeOesophagus

Chewing breaks food into smaller chunks and saliva is addedMouth

Large molecules of food broken down into smaller onesDigestion

Digestive systemDigestive System

BIOLOGY: HEALTH KNOWLEDGE ORGANISER

Lesson 1 - Nutrients Setting the scene Have you ever wondered what is in your food? Different foods contain different amounts of nutrients. It is important to know which nutrients you are eating. In this activity you will find out how nutritious the cereals you eat for breakfast are.

AimsIn this activity you will: interpret nutritional information on food labels make informed judgements on how healthy different foods are.

You will be using enquiry processes to: Analyse: interpret observations and data, including identifying patterns and using

observations, measurements, and data to draw conclusions.

Task1 Look at the nutritional information on the breakfast cereal packets. It will tell you

which nutrients each cereal contains.2 Design a suitable table to record the amount of each nutrient present in 100 g of

each cereal.

Questions1 Name the cereal with the highest amount of each nutrient.

2 Pick four of the nutrients listed in your table. Describe the function of each one in your body.

3 a Compare the carbohydrate content of the products.

b Some of the carbohydrates in the cereals are present as sugar. Name the cereal that contains the most sugar.

c Suggest one negative effect on health of high sugar content in foods.

d From the information on carbohydrates alone, select the healthiest cereal for breakfast. Explain your answer.

4 Use your scientific knowledge and the data obtained to choose the healthiest breakfast cereal overall. Explain your answer.

Extension 1 State the definition of a ‘balanced diet’ and explain why it is necessary to eat a

selection of foods containing all the different nutrients.

2 Some chocolate-coated cereals are considered to be highly processed.Using the information in your table and your answers to the questions above, suggest reasons why processed foods are considered less healthy.

3 E numbers are codes for additives that include colours, preservatives, antioxidants, and thickeners. Suggest some advantages and disadvantages of using E numbers in foods.

Food testsAims In this lesson you are given a question to answer. You will find the answer to this question by learning how you can test for different types of food. You will then write your answer to the question. Big Question

What I need to know Before answering a 6-mark question you should always think about the information you need to know to answer it. The table below states the things you need to be able to do to answer the question. You might not know how to answer all of them yet. Tick the box for the answers you know, and write your answer in the answer box.

Learning objective Answer

Name the components of a healthy diet.

Describe how to test foods for starch, lipids, sugar, and protein.

Describe the positive result for each food test.

Key wordsAdd all the key words you need to answer the Big Question in this box.

Explain in detail how you would test a gingerbread-biscuit solution for the presence of starch, sugar, and protein. (6 marks)

Answer to the Big Question Now you need to write your answer to the question. This is an extended response question. This means you will be marked on: spelling grammar organising your ideas and information clearly using key scientific words.

Write your answer in the space below.

Lesson 2 - Investigating the energy content of foodSetting the scene We get our energy from our food. Different foods contain different amounts of energy. It is important for us to know how much energy our food contains.

AimsIn this practical you will: measure the energy content of various foods.

You will be using enquiry processes to: Enquire: use appropriate methods, paying attention to health and safety Enquire: make and record observations Analyse: interpret observations to identify patterns and draw conclusions.

Safety Take care when using glassware. Take care when using the Bunsen burner. Take care when using a needle to burn the food. The needle may be sharp. Tell your teacher if you are allergic to any of the foods. Wear eye protection.

Equipment and materials eye protection clamp stand clamp boss boiling tubes thermometer 20 cm3 measuring cylinder needle with wooden handle Bunsen burner heatproof mat food samples paper towels

Method1 Accurately measure out 10 cm3 of tap water using a measuring cylinder.2 Pour the water into a test tube. Add a thermometer and record the initial

temperature of the water.3 Set up the equipment as shown. Clamp the test tube in place on a clamp stand. It

should be about 15 cm from the bottom of the stand.

4 Place one piece of food carefully on the end of a needle.5 Hold the food in a Bunsen flame until it catches light.6 Immediately hold the burning food about 5 cm under the tube of water.7 Hold until the food has burned fully and record the final temperature of the water.8 Repeat this method for all the foods supplied. Results Design a suitable table to record your observations and results. Your table must include a column for the temperature difference of the water.

Questions1 Why does the water increase in temperature?

2 Name the food that gave the biggest temperature increase.

3 Name the chemical food group that transferred the most energy to the surroundings. Explain how you can tell using your observations and data.

4 Suggest three ways our bodies use energy.

5 Compare the energy requirement of an office worker compared to a construction worker. Suggest one food for each of them. Explain your answer.

Extension 1 Add a column for ‘energy transferred (J)’ to your results table. Calculate the energy

transferred by each food using the equation:energy (J) = volume of water (cm3) × 4.2 (J/g/°C) × temperature difference (°C)

2 Name the food that contained the most energy.

3 Suggest why it could be important to know about the energy content of different foods.

4 A typical 13-year-old boy requires 10 000 kJ of energy per day. Use the data in your results table to suggest what he should eat in a day. Show your working and explain whether this is a healthy diet.

5 Which variables did you control in your investigation?

6 Suggest one additional variable you could have controlled to improve your results.

Lesson 3 - The digestive system

Setting the scene Your digestive system is an example of an organ system in which several organs work together to digest and absorb food. Each organ has special adaptations to help it perform its function.

To help people understand what happens inside the human body, scientists often use models.

AimsIn this activity you will: identify the main organs in the human digestive system produce a simple model of the human digestive system evaluate how well your model represents key features of the

digestive system.

You will be using enquiry processes to: Communicate: communicate ideas and construct explanations Communicate: critique your model and justify opinions.

Safety Take care when cutting wire – the ends can be sharp. Report any liquid spillages immediately to your teacher.

Equipment and materials plastic tubing modelling clay coloured card / paper large sheets of cardboard / card sticky notes sticky tape food dye / coloured liquid funnel wire / string scissors

TaskYou need to work in a small group to produce a simple model of the human digestive system. On your model you need to add labels to identify the key structures and describe their features.Once you have finished your model you need to pour a coloured liquid through your model to show how food moves through the digestive system.

PlanLook at the materials provided by your teacher and come up with a plan for building a model digestive system. In the space below draw a labelled diagram of what your model will look like including the materials you will be using for each component.

When your teacher has checked you plan build your model digestive system.

EvaluationModels are never perfect. Complete the table below to describe the ways in which your model reflects the real digestive system and they ways it does not accurately represent the digestive system.

Positive features of the model Negative features of the model

Questions1 State what is meant by digestion

2 Put the following structures in the order that food will pass through on its journey through the digestive system.

mouth rectum small intestine stomachlarge intestine gullet anus

3 Match the following organs to their function.

Rectum Food passes down this tube.

Gullet Faeces are stored here until they leave the body.

Stomach Water passes back into the body and faeces are formed.

Small intestine Small molecules of nutrients pass through the intestine wall into the bloodstream.

Large intestine Food is mixed with digestive juices and acids

4 Describe one way your model helps make understanding the key features of the digestive system easier.

5 Describe one improvement you could make to your model digestive system.

6 Evaluate how well your model represents the key features of the digestive system.

Extension 1 Describe how the stomach is adapted to its function.

2 Explain how the small intestine is adapted to its function.

3 Explain how the intestine is adapted to move food along the digestive system.

Investigating enzyme actionSetting the sceneOrgans in the digestive system need help breaking down food. Without bacteria and enzymes, digestion would be far too slow. Enzymes are a special group of proteins that speed up reactions. You are going to investigate enzyme action.

AimsIn this practical you will: investigate the effect of an enzyme on a large carbohydrate (starch).

You will be using enquiry processes to: Enquire: use appropriate methods in experimental work Enquire: complete a hypothesis and prediction Enquire: make and record observations Analyse: present observations in an appropriate table Analyse: evaluate data Communicate: present reasoned explanations.

Safety Do not touch the enzyme solution as it is an irritant. Iodine solution could be an irritant. Wear eye protection.

Equipment and materials eye protection two boiling tubes boiling-tube rack 10 cm3 measuring cylinder glass rod two pipettes spotting tiles stopwatch label pens iodine solution 1% starch solution 1% carbohydrase (diastase) solution distilled water

Hypothesis You already know that when starch is added to iodine it turns a blue-black colour. In this investigation you are going to add an enzyme (carbohydrase) to a starch solution (carbohydrate). You will then add the starch solution to iodine over time. Complete the hypothesis below by crossing out the incorrect words.

When an enzyme/a chemical (carbohydrase) is added to starch/sugar (a carbohydrate), it will break the starch/sugar down. Eventually, it will be fully

broken down into smaller parts. This is because enzymes/chemicals are biological catalysts.

PredictionUse your hypothesis to complete the prediction by crossing out the incorrect words.

I am going to investigate this by adding carbohydrase/iodine to a starch solution. I will then add this to carbohydrase/iodine at different time intervals. I predict that, over time, the starch and carbohydrase solution will stop/keep turning the iodine blue-black. This is because iodine is a test for starch/sugar, and the carbohydrase/iodine will have broken the starch/sugar down.Method1 Collect two spotting tiles.2 Label one row on each spotting tile ‘A’ and another row ‘B’.3 Add a small drop of iodine in each well using a dropping pipette (as shown in the

diagram).

4 Collect two test tubes and label these A and B.5 Measure out 5 cm3 of starch solution using the measuring cylinder.

6 Pour into test tube A.7 Measure out another 5 cm3 of starch solution using the measuring cylinder. Add to

test tube B.8 Measure out 5 cm3 of distilled water using a measuring cylinder and add to test

tube A.9 Mix contents of test tube A (solution A) immediately using a glass rod.10 Measure out 5 cm3 of 1% carbohydrase using a measuring cylinder. Add to test tube

B.11 Mix contents of test tube B (solution B) immediately using a glass rod and start the

stopwatch.12 Using two clean dropping pipettes, add one drop of solution A into the first well on

the spotting tile for row A, and one drop of solution B into the first well on the spotting tile for row B.

13 Continue adding one drop of solutions A and B from their respective test tubes into a new well of the spotting tile every minute.

14 Continue doing this until the colour stops changing for one of the solutions.15 Record all observations.

Results Design a suitable table to record your observations over time. You must include in your table the chemicals used in test tubes A and B.Questions1 Describe your observations for row A.

2 Describe your observations for row B.

3 Suggest an explanation for your observations.

4 Do your results support your hypothesis and prediction? Explain your answer.

5 How long did it take for the starch to break down into sugar?

6 Describe the role of enzymes in the human body.

Extension 1 Explain the purpose of solution A.

2 Suggest an improvement to your method that would have given you more accurate results.

Reviewing key questions from Heath & Lifestyle topic

Key Question 1: Name all the nutrients needed for a healthy diet.

Key Question 2: Give an example of a food containing carbohydrate and explain why we need carbohydrates.

Key Question 3: Explain why I shouldn’t eat a cereal bar with every meal using

evidence from the food label.

Key Question 1: State what you observe when iodine solution is added to starch.

Key Question 2: Write a brief method of how to test for sugar.

Key Question 3: A food sample was tested in Benedict’s and Biuret’s solution. At the end of the test, the Benedict’s was blue and the Biuret’s reagent was purple. Which nutrients are present in this food?

Key Question 1: State what happens if someone ate more calories in their food than the recommended daily allowance.

Key Question 2: Explain the cause of night-blindness.

Key Question 3: Explain why the daily recommended calorie intake for a builder is greater than a computer engineer.

Key Question 1: State what nutrient releases energy quickly in the body.

Key Question 2: How can we test the amount of energy stored in a corn flake?

Key Question 3: Explain what it means for your results to be reproducible.

Key Question 1: State the order of organs the food passes through in the digestive system.

Key Question 2: Describe the function of the small intestine.

Key Question 3: Explain how the small intestine is well adapted to its function.

Key Question 1: State the role of bacteria in the digestive system

Key Question 2: State the function of an enzyme and give an example of the action of a digestive enzyme.

Key Question 3: Explain why we need enzymes in our digestive system.

Key Question 1: Why do we use models in science?

Key Question 2: Explain what a random error is.

Key Question 3: Explain how to reduce the impact of random error on your results.

Key Question 1: State 2 examples of a recreational drug.

Key Question 2: Explain the difference between medicinal and recreational drugs.

Key Question 3: Explain what drug addiction is.

Answers to Lesson 1 - NutrientsQuestions1 Depends on the cereals used.2 Any four from:o fat – provides energy, insulation, and protection

o vitamins – keep the body healthy

o minerals – keep the body healthy

o protein – growth and repair

o carbohydrate – provides energy

o water – needed in all cells and body fluids

o fibre – provides bulk to keep food moving through the gut

3 a Depends on the cereals used.b Depends on the cereals used (likely to be the highly processed cereal).c obesityd Depends on the cereals used.

4 Depends on the cereals used. The cereal with the lowest fat and sugar content and the fewest additives. Quote correct figures. Reduces specific health problems for each nutrient mentioned.

Extension 1 A balanced diet contains the right nutrients in the right amounts for the body’s

needs. Each nutrient has a different function in the body. (Provide examples, e.g., carbohydrates for energy.)

2 Processed foods generally have higher quantities of sugar, fat, and additives. These are parts of a diet you should only eat small amounts of. (Link to specific health problems.)

3 Advantages: increase shelf life, improve taste, and give better colour.Disadvantages: can cause hyperactivity, not a nutrient so have no benefit to the body.

Answers to Big Question on Food testsExplain in detail how you would test a gingerbread-biscuit solution for the presence of starch, sugar, and protein. (6 marks)

For students to be able to answer the question, they need to:

Learning objective AnswerName the components of a healthy diet.

carbohydrates (provide energy)lipids (provide energy)proteins (for growth and repair)vitamins (keep you healthy)minerals (keep you healthy)water (needed in all cells and body fluids)fibre (provides bulk to food to keep it moving through the gut)

Describe how to test foods for starch, lipids, sugar, and protein.Describe the positive result for each food test.

starch add a few drops of iodine to the food solution look for a colour change (orange to blue-black shows

starch is present).lipids rub some of the food sample onto a piece of filter

paper hold the paper up to the light. If the paper appears

translucent lipids are present. sugar add a few drops of Benedict’s solution to the food

solution heat the test tube in a water bath if the solution turns orange-red the food contains

sugar. protein add a few drops of copper sulfate solution to the

food solution add a few drops of sodium hydroxide solution if the solution turns purple, the food contains

protein.

Question marking guidance Explain in detail how you would test a gingerbread-biscuit solution for the presence of starch, sugar, and protein. (6 marks)

1–2 marks There needs to be a basic description of the solutions involved in the tests. Students need to have stated at least one solution and positive result correctly. Students also need to have included at least three of the scientific points listed below.

3–4 marksThere needs to be a clear description of the solutions involved in the tests and how to use them. Students need to have described at least two correct solutions and positive results. Students should give at least six of the scientific points given below. Spelling and grammar is mostly correct, and the answer is presented logically.

5–6 marksThere is a full and detailed description of the solutions involved in the tests and how to use them. Students need to have described all three methods and positive results. The answer is well structured and spelling and grammar nearly all correct. Students should give at least nine of the scientific points given below.

Scientific points The gingerbread-biscuit solution can be tested using chemical food tests. The test for starch uses iodine solution. Add a few drops of iodine solution to the gingerbread-biscuit solution. If the solution turns blue-black then starch is present. The test for sugar uses Benedict’s solution. Add a few drops of Benedict’s solution to the gingerbread-biscuit solution. Heat the

test tube containing the solutions in a water bath. If the solution turns orange-red, the food contains sugar. The test for protein uses copper sulfate solution and sodium hydroxide solution. Add a few drops of copper sulfate solution to the food solution. Add a few drops of sodium hydroxide solution. If the solution turns purple, the food contains protein.

Starter Support/Extend ResourcesIntroducing the question (5 minutes)Give students the Question-led lesson student sheet and write the Big Question on the board. Explain to students that by the end of this lesson, they will be able to answer the question. Students should record key words and answers to the question requirements table as they move through the lesson. Testing not tasting (5 minutes) We like food that tastes nice, but we need to know what each food contains. Ask students how they think scientists can learn what nutrients are present in food. Lead the discussion to the idea of doing chemical tests, and how scientists need clear results to tell us whether a food contains a nutrient or not.

8.4.2 Activity: Question-led lesson

Main Support/Extend ResourcesFood tests (30 minutes) Introduce the tests for starch, lipids, sugar, and protein, and observations for positive results in each experiment.Students work in small groups to carry out a circus activity where they will test the presence of starch, lipids, sugar, and protein in the foods provided for themselves during their allocated time at each station. For the purpose of this lesson students do not need to answer the questions on the practical sheet. They can instead move onto the question-led activity. An interactive screen is available for this lesson which links foods to their tests and positive results. This could be displayed on the whiteboard for students to complete as they finish the circus. Question-led activity (10 minutes)Students answer the Big Question and then use the mark scheme to check their answers.

Support: A suggested results table is provided in the accompanying support sheet for students to use when recording observations

8.4.2 Practical: Food tests8.4.2 Interactive: Food tests and results

Answers to Lesson 2 – Energy content in food

Questions1 When the food is burned, energy in the food is transferred to the surroundings. This

heats the water (energy is transferred from the surroundings to the particles in the water).

2 Depends on students’ results.3 fats and carbohydrates4 Maintaining body temperature, movement, and repair.5 An office worker sits down all day, not using a lot of energy. A construction worker

moves around more so uses more energy. The office worker should eat lower-energy foods (i.e., low-fat foods). The construction worker should eat higher-energy foods (i.e., high-carbohydrate foods).

Extension 1 Answers will depend on students’ results. Check the calculations are correct and that

units have been included in their answer.

2 Depends on students’ results. It is likely to be the ‘fattiest’ or most carbohydrate-rich food.

3 People will have different energy requirements depending on their lifestyle or health.4 This will depend on the students’ results and the foods supplied. Take into account

the foods supplied when assessing students’ answers to whether this is a balanced diet. Correct answers should contain reference to nutrients, why they are important, and whether they are present.

5 Volume of tap water, distance of burning food beneath test tube. 6 Each food sample has a different mass. An additional control variable could have

been the mass of the food sample.

Answers to Lesson 3 – Digestive system PlanAll students should produce a plan which shows the position of the main structures in the digestive system (mouth, gullet, stomach, small intestine, large intestine, rectum, anus). Students should state the material they are going to use to represent each organ and may add the information they are going to include to the description label.EvaluationAll students should include at least one positive feature and one negative feature of their model.Positive examples could include: Shows the position of the organs in the digestive system. Shows the order of the structures the food passes through in the digestive system. Shows some differences in organ structure.

Negative examples could include: Movement of liquid relies on gravity – doesn’t show peristalsis (squeezing of food). Detailed internal structure of organs may not be seen – for example villi in small intestine. Doesn’t show absorption / enzymes being added.

Questions1 The breakdown of large (insoluble) food molecules into small (soluble) molecules.2 Mouth, gullet, stomach, small intestine, large intestine, rectum, anus.3

4 One advantage of their model described (see earlier examples in evaluation).5 One appropriate improvement suggested for their model.6 Students should formulate an evaluation through reference to their positive /

negative features table, and questions 4 and 5. Students may need guidance to help them formulate an effective evaluation – ensure they include both positive and negative aspects of their model, and a critique of the overall effectiveness of the model in providing an explanation of, or deepening understanding of, the human digestive system.

Extension1 Contains acid to destroy bacteria and muscular wall to churn food and mix with acid and

digestive juices (enzymes).2 Intestine wall is thin, covered with tiny projections (villi) to increase surface area and has a

rich blood supply this speeds up the rate of absorption and then carries away food molecules to where needed.

3 Muscle walls contract/squeeze pushing food along intestine. (This is called peristalsis).

Answers - Investigating enzyme actionHypothesisWhen an enzyme (carbohydrase) is added to starch (a carbohydrate) it will break the starch down. Eventually, it will be fully broken down into smaller parts. This is because enzymes are biological catalysts. PredictionI am going to investigate this by adding carbohydrase to a starch solution. I will then add this to iodine at different time intervals.

I predict that, over time, the starch and carbohydrase solution will stop turning the iodine blue-black. This is because iodine is a test for starch, and the carbohydrase will have broken the starch down.Questions1 At 0 minutes, the iodine solution turned from orange to blue-black when solution A

was added. The same happened at each one-minute interval when solution A was added.

2 At 0 minutes, the iodine solution turned from orange to blue-black when solution B was added. Students should note that after a certain number of minutes, the colour did not change (for each new dimple in the row on the spotting tile).

3 Solution A had no enzyme in it. This means the starch did not break down. The iodine changed colour as there was starch in the solution. Solution B contained the enzyme carbohydrase. At 0 minutes the iodine changed colour because starch was present. The enzyme had not broken down the starch yet. After a certain number of minutes, the colour did not change because the starch had been broken down into sugar. Iodine does not test for sugar (the test for sugar uses Benedict’s solution).

4 If carried out correctly, the students should conclude that their results do support their hypothesis and their prediction was correct. They should cite observations and their explanations in their answer.

5 Time in minutes dependent on student’s results. 6 Enzymes are known as biological catalysts. They speed up digestion without being

used up. The enzymes in the digestive system break down large molecules (nutrients) into small ones. These smaller molecules can then be used for other processes in the body.

Extension1 Solution A was a control. The control was needed to show that our observations were

the result of adding the enzyme, and not any other factors. 2 Example: test for sugar at the same time as testing for starch, to show that the

enzyme is breaking down starch into sugar.

Answers to Key questions on Health & Lifestyle topic

Key Question 1: State where the non-metal elements are found on the periodic table.Expected answer: On the right hand side (of the staircase)Key Question 2: Describe some physical properties of non-metals.Expected answer: Poor conductor or heat, poor conductor of electricity, dull, low density, brittle, not sonorousKey Question 3: Are the following substances metals or non metals?Expected answer:A – non-metalB - metalC - metal

Key Question 1: Name all the nutrients needed for a healthy diet.Expected answer: Protein, carbohydrate, fat, fibre, water, vitamins and minerals.Key Question 2: Give an example of a food containing carbohydrate and explain why we need carbohydrates.Expected answer: Potatoes, bread, pastaSource of quick releasing energyKey Question 3: Explain why I shouldn’t eat a cereal bar with every meal using evidence from the food label.Expected answer:One cereal bar is 38% of your sugar so I you had 3 per day that it over the recommended daily amount of sugar. 3 cereal bars is also 39% of your recommended daily calorie intake which only leaves 61% for the rest of your food.

Key Question 1: State what you observe when iodine solution is added to starch.Expected answer: The colour of iodine solution changes from brown to black.Key Question 2: Write a brief method of how to test for sugar.Expected answer: 1. Add Benedict’s solution to the food sample2. Heat the test tube in a water bath3. If the colour changes from blue to orange/red then there is sugar presentKey Question 3: A food sample was tested in Benedict’s and Biuret’s solution. At the end of the test, the Benedict’s was blue and the Biuret’s reagent was purple. Which nutrients are present in this food?Expected answer:Protein[there is no sugar as the Benedict’s test was negative]

Key Question 1: State what happens if someone ate more calories in their food than the recommended daily allowance.Expected answer: They will become overweight.Key Question 2: Explain the cause of night-blindness.Expected answer: Lack of vitamin A in the diet.Key Question 3: Explain why the daily recommended calorie intake for a builder is greater than a computer engineer.Expected answer:Builders use up more energy to move everyday in their jobs compared to a computer engineer who mostly sits still at the computer and uses up less energy.

Key Question 1: State what nutrient releases energy quickly in the body.Expected answer: Carbohydrates (starch and sugar)Key Question 2: How can we test the amount of energy stored in a corn flake?Expected answer: 1. Burn it under a known amount of water in a test tube2. Measure the increase in water temperature as it burnsKey Question 3: Explain what it means for your results to be reproducible.Expected answer:Someone else does the same method using different equipment but gets the same result.

Key Question 1: State the order of organs the food passes through in the digestive system.Expected answer: Mouth, oesophagus, stomach, small intestine, large intestine, rectum, anusKey Question 2: Describe the function of the small intestine.Expected answer: To absorb nutrients from the small intestine into blood.Key Question 3: Explain how the small intestine is well adapted to its function.Expected answer:1. Many villi which increase the surface area to increase movement/absorption of nutrient molecules into blood2. Very long which increase the surface area to increase movement/absorption of nutrient molecules into blood3. Good blood supply which allows nutrient molecules to be absorbed into blood

Key Question 1: State the role of bacteria in the digestive system Expected answer: Bacteria in the intestines help to break down food.Bacteria can make vitamin K which we need for healthKey Question 2: State the function of an enzyme and give an example of the action of a digestive enzyme.Expected answer: - An enzyme speeds up chemical reactions in the body. - Lipase works by breaking a lipid molecule down into glycerol and fatty acids.Protease works by breaking a protein molecule down into amino acidsCarbohydrase works by breaking a carbohydrate molecule down into simple sugars.Key Question 3: Explain why we need enzymes in our digestive system.Expected answer:Large nutrient molecules cannot be absorbed into blood/pass through the cell membranes of the small intestine if too large, so enzymes break them down into smaller molecules.

Key Question 1: Why do we use models in science?

Expected answer: to understand how things that we cannot see work.

Key Question 2: Explain what a random error is.

Expected answer: Random error is when an incorrect result, caused by something random, is recorded in your results.

Key Question 3: Explain how to reduce the impact of random error on your results.

Expected answer:

Take more samples and calculate the mean.

Key Question 1: State 2 examples of a recreational drug.Expected answer: Caffeine, alcohol, tobacco/nicotine, cocaine.Key Question 2: Explain the difference between medicinal and recreational drugs.Expected answer: Medicinal drugs benefit health and treat diseaseRecreational drugs are taken for enjoyment or how they make you feel (e.g. awake)Key Question 3: Explain what drug addiction is.Expected answer:When the body becomes dependent on a drug so you have to keep taking it to feel normal.

Key Question 1: Describe what ‘units’ of alcohol are.Expected answer: A ‘unit’ tells you how much alcohol is in an alcoholic drink.Can be used to inform people of how much alcohol they are drinking.Key Question 2: Explain why it is illegal to drive if someone has drunk 4 glasses of wine.Expected answer: Alcohol is a depressant so it slows down reactions and coordination.If you are driving a car then you do not have normal control of the car and are likely to have an accident and hurt yourself and others.Key Question 3: Explain why pregnant women should not drink any alcohol.Expected answer:Alcohol (ethanol) passes into the foetus’ blood through the placenta and umbilical cord which can cause:- problems in brain development (causing learning difficulties)- foetal alcohol syndrome- Death of foetus (miscarriage or stillbirth)

Key Question 1: State 3 diseases that a smoker is more likely to suffer from.Expected answer: Lung cancer, throat cancer, respiratory infections, heart disease, emphysema Key Question 2: Explain the effect on the foetus of smoking during pregnancy.Expected answer: Chemicals pass into the foetus’ blood through the placenta and umbilical cord which can cause:- Problems in growth / low-birth weight- Miscarriage- Development problemsKey Question 3: Explain the effect carbon monoxide, nicotine and tar have on the body.Expected answer:Carbon monoxide – poisonous gas that stops red blood cells carrying oxygenNicotine – stimulant drug which speeds up heart rate, very addictiveTar – collects in lungs, causes cancer, makes cilia stick down in airways = coughing

Lesson 4 - Patterns, groups, and periods in the Periodic TableSetting the scene The Periodic Table shows all the chemical elements. They are shown in groups and periods. There are patterns in the properties of elements down groups and across periods.

AimsIn this activity you will: label a Periodic Table sort elements using chemical data and relate this to their positions in the Periodic Table.

You will be using enquiry processes to: Analyse: interpret observations and data to identify patterns and draw conclusions Analyse: discuss limitations Analyse: present data about the Periodic Table Communicate: communicate ideas and construct explanations Solve: understand how scientific ideas have changed.

Task1 Using different coloured highlighter pens or different types of shading, colour in

each of the following groups: Group 1 Group 2 Group 7 Group 0

2 Use a dark pen to draw a line in the following position:

3 The line you have just drawn divides the Periodic Table into metals and non-metals. Add the following labels in large, clear writing in the positions given: ‘Metals’ to the left of the stepped line ‘Non-metals’ to the right of the stepped line

Questions1 The table shows the melting points of the elements in Group 1 and Group 2

of the Periodic Table. The melting point of magnesium is not included.The elements are listed in the same order as they are in the Periodic Table.Group 1 element Melting point

(°C)Group 2 element Melting point

(°C)

lithium 180 beryllium 1287

sodium 98 magnesium

potassium 64 calcium 842

rubidium 39 strontium 777

caesium 28 barium 727

a Draw a bar chart to present the data for Group 1.Write the element names on the x-axis and an even temperature scale on the y-axis.

b Copy and complete the sentence below to describe the pattern on your bar chart.

From top to bottom of Group 1, the melting point .c Now draw a bar chart to present the data for Group 2. Leave a space for

magnesium.d Use your Group 2 bar chart to answer the following questions.i Describe the pattern shown on the Group 2 bar chart.

ii Use your graph to predict the melting point of magnesium.

iiiThe measured melting point of magnesium is 650 °C. Suggest a limitation in using the Periodic Table to make predictions based on patterns.

2 The table gives some data about five elements. Each element is represented by a letter. The letters are not the chemical symbols of the elements. Remember: Most metal oxides are basic and solid at room temperature. Most non-metal oxides are acidic and are gases at room temperature.

Element Melting point (°C)

Boiling point (°C)

What is the state of the oxide of element at room temperature?

Is the oxide of the element acidic, basic, or neutral at

room temperature?

V 1083 2595 solid can behave as both an acid and a base

W 113 445 gas acidic

X 98 890 solid basic

Y −210 −196 gas acidic

Z −101 −35 gas neutral

a Give the letters of two elements in the table that are definitely non-metals.

Explain how you know that these elements are non-metals.

b Give the letter of one element in the table that is definitely a metal.Explain your decision.

c Look at the data for the other two elements. For each, discuss with another student whether it is most likely to be a metal or a non-metal. Explain your decisions to each other and then write them down clearly.

d State which of the elements V, W, X, Y and Z in the table above are found on the left of the stepped line in the Periodic Table, and which are on the right.

Left of stepped line:

Right of stepped line:

Extension 1 Dmitri Mendeleev was a chemist who made predictions about elements that had not

yet been discovered. One of the elements he made predictions about was gallium. He originally called gallium ‘eka-aluminium’. Look at the Periodic Table and suggest why he may have given the undiscovered element this name.

2 Aluminium has a density of 2.70 g/cm3. Boron has a density of 2.08 g/cm3. Predict the density of gallium. Explain your answer.

3 Classify the properties discussed in Question 2 and Extension Question 2 as chemical or physical properties. Explain your answer.

How do Group 1 elements react with water? Setting the scene Elements in the same group can show patterns in the way they behave. Group 1 elements all react with water – but do they all behave in the same way when they are added to water?AimsIn this activity you will: record observations on demonstrations of the reactivity of Group 1 elements with water identify a pattern in behaviour identify the products formed and some of the product properties.

You will be using enquiry processes to:

Enquire: make observations about what you see Enquire: predict what you would expect to see for other elements in the same group.

Safety Wear chemical splash-proof eye protection. Remain two to three metres away from the safety screen until told otherwise.

TaskYou will watch demonstrations of how the first three Group 1 elements react with water. Record your observations in the results table.

ResultsRecord your observations in the table below.

Group 1 element Observations

lithium

sodium

potassium

Questions1 State whether Group 1 elements are metals or non-metals. Explain your answer

using the Periodic Table.

2 From your observations, state what you know about the two products of the reactions. Explain your answers.

3 What are the products of this reaction? Tick the correct answer.

a oxygen and metal chloride

b hydrogen and metal hydroxide

c hydrogen and sulfuric acid4 Describe what happens to the product of this reaction that is not a gas.

5 The word equation for the reaction between lithium and water is shown below:

lithium + water → lithium hydroxide + hydrogen

Write word equations for the reactions of sodium and potassium with water.

6 Choose the correct words to complete the following sentence about the reactivity of the Group 1 elements:The reactivity decreases/increases as you move down through the elements of Group 1. The elements at the bottom of the group react more/less vigorously with water compared to the elements at the top.

7 Rubidium (Rb) and caesium (Cs) are also Group 1 elements. Predict what observations you would see if they reacted with water.

Extension 1 Explain your answer to Question 7. Compare your predictions with a video of these

reactions.

2 Universal indicator solution can give an indication of the pH of the metal hydroxide solution. Suggest a more accurate way of determining the pH.

Lesson 5 - Displacement of halidesSetting the scene The elements of Group 7 are known as the halogens. Observing their reactions can tell you how reactive each element is. Halogens are extremely hazardous and must be handled with care when used. Scientists write risk assessments before using chemicals so people know how to keep safe in an experiment.

AimsIn this activity you will: make observations on reactions of halogens determine the reactivity of the halogens look at hazard symbols to decide what they mean suggest safety precautions for using Group 7 elements.

You will be using enquiry processes to: Solve: evaluate risks and hazards Analyse: interpret observations to identify patterns and draw conclusions.

Task 1 Your teacher is going to demonstrate how each Group 7 element dissolved in water

(called halogen water) reacts with solutions of Group 7 compounds. A more reactive halogen will displace a less reactive halogen element from its

compounds. Fill in the following table with your observations.

Halogen water used

Observations when added to

potassium chloride solution

Observations when added to

potassium bromide solution

Observations when added to

potassium iodide solution

chlorine water

bromine water

iodine water

1 State what is meant by a displacement reaction.

2 State three possible observations during any chemical reaction.

3 Describe the observation in this experiment that demonstrates a chemical reaction has taken place.

4 Use your observations above to write an order of reactivity for the halogens, starting with the most reactive. Explain your answer using your observations.

Extension1 Write word equations for the displacement reactions that took place.

2 Using the pattern in reactivity for Group 7 elements, predict if chlorine water will react with lithium fluoride. Explain your answer.

Task 2Look at the picture of Group 7 elements below:

1 Write the hazards shown for each of the Group 7 elements shown. Use the table below.

Group 7 element Hazard symbol Description of hazard

chlorine

bromine

iodine

2 List any safety measures needed when using Group 7 elements. Remember that each of the elements is either a gas or is able to turn easily into a gas at room temperature. For each safety precaution you give, you should explain why it is necessary.

Extension Risk assessments are usually completed in ready-made grids. Use the information above to complete the following risk assessment.

Choose from the answers below to help you complete the last column. You can use the answers more than once and you can have more than one answer for each hazardous substance. Some of the answers provided will not be relevant.

Possible actions that can be taken in the event of injuries/contact with substances: shut windows and doors get into fresh air seek medical attention open windows wash skin thoroughly with plenty of water apply hand cream use air freshener drink milk inform laboratory technician inform emergency services

Risk assessment for halogen displacement reactions

Hazardoussubstance

Who is at risk from this

substance?

Safety measures required when

using this substance

Actions needed ifinjury/contact

with hazardous substance

Trends in the noble gasesSetting the scene The Group 0 elements are known as the noble gases. They are unreactive, which means they do not react easily. They show some patterns in their chemical and physical properties. For example, the elements lower down the group are slightly more reactive than those at the top of the group.

AimsIn this activity you will: plot data on the noble gases describe the trend or pattern you see predict the missing value from your graph.

You will be using enquiry processes to: Analyse: present data in an appropriate graph Analyse: interpret data to identify patterns and draw conclusions Communicate: present explanations of the data.

TaskAll elements have a certain mass relative to each other. This mass is called the relative atomic mass. A table showing the relative atomic masses for the noble gases is shown below. The value for krypton is missing.

Noble gas element Relative atomic mass (u)

helium 4

neon 20

argon 40

krypton

xenon 131

1 Plot a suitable bar graph of the values in the table. Leave a gap for krypton.Make sure you plot the data in the order shown.Label your axes fully.

3 Look at your graph. Using a pencil, draw a bar for the atomic mass you think krypton would have. Fill in the missing value in the table above.

Questions1 Complete the following sentence by choosing the correct words:

The atomic mass of the noble gas elements decreases/increases as you move down the group from helium to xenon. This means the elements get heavier/lighter as you move down the group. Noble gases are generally very reactive/non-reactive.

2 State your predicted value for the relative atomic mass of krypton. Explain how you chose this answer.

Extension 1 Radon is the next noble gas after xenon down the group. Predict how radon’s relative

atomic mass compares with that of xenon.

2 Argon is often used to fill the space between glass panes in double-glazed windows. If the glass was accidentally broken the argon would escape. Would this be safe? Explain your answer.

3 Explain whether drawing a bar graph of the atomic masses of the noble gases is an accurate way of predicting the missing value for krypton.

4 Suggest why compounds such as xenon fluoride are known but compounds such as neon fluoride are not.

Key questions on Periodic table topic

Key Question 1: State where the non-metal elements are found on the periodic table.

Key Question 2: Describe some physical properties of non-metals.

Key Question 3: Are the following substances metals or non metals?

Key Question 1: What is the difference between a group and a period on the periodic table?

Key Question 2: Describe a pattern of the elements along period 2 from left to right.

Key Question 3: Use this group 7 data to predict the melting point of chlorine.

Key Question 1: State the name that group 1 elements are also known as.

Key Question 2: State what would be observed when potassium reacts with water.

Key Question 3: Describe trend of reactivity as the elements go down group 1.

Key Question 1: Describe the trend in reactivity as you go down group 7 elements.

Key Question 2: Fluorine has a boiling point of -188°C. What state is fluorine at room temperature?

Key Question 3: Complete the word equation for this reaction:

Key Question 1: Which has the highest boiling point, helium or xenon?

Key Question 2: Describe the trend in reactivity in group 0.

Key Question 3: Explain a difference between group 0 and group 7 elements.

Answers Lesson 1 - Patterns, groups, and periods in the Periodic TableQuestions1 a A correctly labelled bar chart, with an even scale on the y-axis, is required.

b From top to bottom of the group, melting point decreases.c A correctly labelled bar chart, with an even scale on the y-axis and a gap for

magnesium.d i From top to bottom of the group, melting point decreases.

ii Any value between 850°C and 1280°C.iii Some properties of some elements do not fit the pattern.

2 a W and Y – they form acidic oxides that are gases at room temperature.b X – it forms a basic oxide that is solid at room temperature.

c V is a metal because it has high melting and boiling points, and its oxide is a solid at room temperature. Z is a non-metal because its melting and boiling points are low, and its oxide is in the gas state at room temperature.

d Left of stepped line: V and X; Right of stepped line: W, Y, and Z.

Extension1 He gave it a name that suggests it will be similar to aluminium as it is below aluminium

in the same group. He predicts it will have similar properties to aluminium.2 The density of gallium is 5.91 g/cm3 but credit any value between this value and 3 g/cm3,

as it shows the student has identified the pattern that density increases down the group. 3 The property in Question 2 is a chemical property. The property in Extension Question 2

is a physical property.

Answers - How do Group 1 elements react with water?Questions1 Group 1 elements are metals. They are found to the left of the ‘steps’ in the periodic

table.2 One product is a gas, as fizzing was observed. The other product is alkaline, as the

universal indicator showed an alkaline pH. 3 hydrogen and metal hydroxide (b)4 The metal hydroxide dissolves in the water.5 sodium + water → sodium hydroxide + hydrogen

potassium + water → potassium hydroxide + water6 The correct words are: ‘increases’ and ‘more’.7 Rubidium will cause more fizzing and a more violent reaction compared with those in the

demonstration. Caesium will cause even more fizzing and an even more violent reaction.

Extension 1 I predict this because I have observed the reaction increases in fizzing and violence down

the group.2 Use a pH probe.

Answers lesson 2 - Displacement of halidesTask 1

Halogen water used

Observations when added to

potassium chloride solution

Observations when added to

potassium bromide solution

Observations when added to

potassium iodide solution

chlorine water No reaction should be observed.

A yellow/brown colour should be seen – this is the colour of the displaced bromine.

A brown colour should be seen – this is the colour of the displaced iodine.

bromine water No reaction should be observed.

No reaction should be observed.

A brown colour should be seen – this is the colour of the displaced iodine.

iodine water No reaction should be observed.

No reaction should be observed.

No reaction should be observed.

1 A reaction where a more reactive element displaces a less reactive element from a compound.

2 Any three from: gases produced/fizzing, colour change, temperature change, reactants used up, new substance appears.

3 colour change4 (most reactive) chlorine, bromine, iodine

Chlorine could displace both the other halogens, so is more reactive than bromine and iodine. Bromine could displace iodine, so is more reactive than iodine.

Extension1 chlorine water + potassium bromide → potassium chloride + bromine

chlorine water + potassium iodide → potassium chloride + iodinebromine water + potassium iodide → potassium bromide + iodine

2 No because fluorine is above chlorine in Group 7. Reactivity decreases down Group 7, therefore fluorine will be more reactive than chlorine. So chlorine will not react with lithium fluoride, as it will not displace the fluorine.

Task 21 Students should have filled in the table with information similar to that shown in the

table below:

Group 7 element Hazard symbol Description of hazard

chlorine toxic Causes serious illness or possibly death, usually through ingestion.

bromine corrosive Causes burns to skin and will

toxicdamage surfaces.

Causes serious illness or possibly death, usually through ingestion.

iodine harmful Can cause severe illness.

2 Students should have covered the following points: Use a fume cupboard (to remove toxic gases). Wear eye protection (to prevent chemicals that could cause burns getting into eyes). Avoid contact with substances (to prevent substances entering the body). Students may have said wear gloves/lab coats (to protect skin and clothes from

burns).

Extension An example of a completed grid is shown below.

Hazard assessment for halogen displacement reactions

Hazardous substance

Who is at risk from this substance?

Safety measures needed when using

this substance

Actions needed if injury/contact with

hazardous substance occurs

chlorine

People carrying out the practical;people nearby as gas spreads

Use a fume cupboard

get fresh air seek medical

attention inform technician

brominePeople carrying out the practical;people nearby as gas spreads

Use a fume cupboard

Wear gloves and eye protection

get fresh air seek medical

attention wash spills off skin

immediately inform laboratory

technician

iodine People carrying out the practical

Wear gloves and eye protection

seek medical attention

wash spills off skin immediately

inform laboratory technician

Answers – The Noble gasesTaskStudents’ bar charts should show the increase in atomic mass down the group. The graph should be checked to ensure it has labelled axes, a title, and correctly sized bars representing the values given in the activity sheet.Questions1 The correct words are ‘increases’, ‘heavier’, and ‘non-reactive’.2 Students should have predicted a value greater than 40 and smaller than 131 and drawn

a bar representing this accordingly. The actual value is 84 u. Credit should be given for predictions close to this value if it is clear this value has been calculated logically.

Extension 1 The mass would be greater. This would follow the trend seen in the earlier elements of

an increase in mass moving down through the group. 2 It would be safe. Argon, along with all the noble gases, is unreactive and so will not react

with anything nearby. It would just diffuse and remain as argon particles.3 It is not completely accurate, but can give an approximate value. It is not completely

accurate as there is not a set increase in atomic mass between each element in the group.

4 Neon is unreactive; there are no known reactions. Xenon is slightly more reactive and hence it forms some compounds with fluorine, which is very reactive.

Answers to Key questions on Periodic table topic

Key Question 1: State where the non-metal elements are found on the periodic table.Expected answer: On the right hand side (of the staircase)Key Question 2: Describe some physical properties of non-metals.Expected answer: Poor conductor or heat, poor conductor of electricity, dull, low density, brittle, not sonorousKey Question 3: Are the following substances metals or non metals?Expected answer:A – non-metalB - metalC – metal

Key Question 1: What is the difference between a group and a period on the periodic table?Expected answer: Groups are vertical columnsPeriods are horizontal rowsKey Question 2: Describe a pattern of the elements along period 2 from left to right.Expected answer: The atomic number increases along the periodThe atomic radium decreases along the periodKey Question 3: Use this group 7 data to predict the melting point of chlorine.Expected answer:Between -80°C to -120°C

Key Question 1: State the name that group 1 elements are also known as.Expected answer: Alkali metals.Key Question 2: State what would be observed when potassium reacts with water.Expected answer: Fizzing, movement on the surface of water, purple flame.Key Question 3: Describe trend of reactivity as the elements go down group 1.Expected answer:The elements get more reactive as you go down group 1.

Key Question 1: Describe the trend in reactivity as you go down group 7 elements.Expected answer: The reactivity of group 7 elements decrease as you go down the group.Key Question 2: Fluorine has a boiling point of -188°C. What state is fluorine at room temperature?Expected answer: A gas.Key Question 3: Complete the word equation for this reaction: fluorine + potassium bromide à ________________________ + ___________________________Expected answer:fluorine + potassium bromide à potassium fluoride + bromine

Key Question 1: State a way you can tell a chemical reaction has taken place.Expected answer: Colour changeKey Question 2: Describe a precaution you would take if using a corrosive chemical.Expected answer: Gloves, goggles, lab coat.Key Question 3: Explain why there is no change when bromine water is added to potassium chloride.Expected answer:Bromine is less reactive than chlorine so does not displace it.

Key Question 1: Which has the highest boiling point, helium or xenon?Expected answer: Xenon Key Question 2: Describe the trend in reactivity in group 0.Expected answer: They are all unreactive.Key Question 3: Explain a difference between group 0 and group 7 elements.Expected answer:Group 0 unreactive, group 7 very reactiveGroup 0 are colourless, group 7 different colours

Lesson 6 - Investigating potential differenceSetting the scene This practical shows you how energy from a power source, such as a battery or power pack, is transferred in a circuit. You will measure potential difference across different components in the circuit to find out how it is shared between these parts.

AimsIn this practical you will: measure potential difference in different parts of a series circuit compare potential difference across different components.

You will be using enquiry processes to: Enquire: use suitable equipment to take measurements Enquire: make predictions using scientific knowledge Analyse: interpret observations and use patterns to draw conclusions.

Safety Be careful when changing the circuit, as wires may be hot. Remember that mains electricity is dangerous.

Equipment and materials battery pack connecting leads voltmeter two bulbs switch optional: motor or buzzer

Method1 Set up the circuit with the battery, bulbs, and switch as in the diagram. Do not

connect the voltmeter until Step 2.

2 Measure the potential difference at positions 1, 2, and 3 in turn. Record the readings in your results table.

3 Repeat Step 2 with one, three, and four cells in your circuit.

Results Draw a suitable table to record your results. You should include units in the table headings where appropriate.

Questions1 State the function of the voltmeter. Include units where appropriate.

2 Describe how the voltmeter was connected in the circuit.

3 Explain why the potential difference changed when you used more cells.

4 Describe the pattern in potential difference when changing the number of bulbs in the circuit.

5 Predict what would happen to the potential difference if the connecting leads of the voltmeter were swapped around.

Extension1 Explain why the potential difference of a component must be measured in parallel,

using the definition of potential difference to help you.

2 Predict how adding even more cells to your circuit would affect the brightness of the bulbs using your ideas about the transfer of energy.

3 Suggest why electricians have to be even more careful when using mains voltage instead of a power supply.

Investigating the resistance of a wireSetting the scene The resistance of a wire depends on several things: its shape, material, and temperature. You will investigate how the length of a wire affects its resistance.

AimsIn this practical you will: measure resistance using a multimeter.

You will be using enquiry processes to: Enquire: make predictions using scientific knowledge Enquire: plan an experiment including independent, dependent, and

control variables Analyse: present data in a graph Analyse: interpret data and identify patterns to draw conclusions.

Safety The wires may become hot. Take care when touching. Handle probes carefully if they are sharp.

Equipment and materials multimeter set to measure resistance probes

length of constantan wire metre ruler

PredictionWrite down your prediction for how the length of wire will affect its resistance. Include as much detail in your prediction as possible.

MethodComplete the following sentences with units where applicable.In this experiment:

The independent variable is

The dependent variable is

The variables I must control are

You need to plan what readings you will take. You have 1 metre (100 cm) of wire to test. 1 Write down the smallest and the largest length you plan to test:

smallest length cm

largest length cm

You will plot a graph of your results, so you need enough results to show a clear pattern.

2 Write down how many readings you plan to take.

3 Write down which lengths you plan to test.

4 How many times do you plan to repeat the readings?

Results Prepare a suitable results table to record your observations. Your table must include: the lengths you plan to test the number of repeats you plan to take the unit you measure resistance in a column to calculate the average reading.

Draw a graph to show your results. Draw the length of the wire (in centimetres) along the x-axis and the resistance (in ohms) along the y-axis. Plot the points and draw a line of best fit.

Questions1 a List three examples of insulators and three examples of conductors.

insulators:

conductors:

b Explain how you can tell whether a material is an insulator or a conductor from resistance readings.

2 Describe the pattern shown on your graph.

3 Suggest how your measurement of resistance would differ if you had used an insulator.

4 Describe what is meant by resistance.

5 If you don’t have a multimeter, you can use a voltmeter and ammeter to find the resistance in a circuit. You will need to.

a Draw on where you should position the voltmeter and ammeter to find the resistance of the wire in the circuit below.

b The voltmeter reads 6 V and the ammeter reads 2 A. Use the formula resistance = potential difference ÷ current to calculate the resistance of the wire.

Extension 1 Explain the causes of resistance and suggest two changes that can be made to the

experiment to alter the resistance readings obtained.

2 The range of readings is the difference between the highest and lowest value. a Explain why you chose the number and range of readings that you did.

b Discuss whether the number and range of readings chosen were suitable for your experiment and suggest one way of improving your experimental procedure.

Lesson 7 - Series and parallel circuits

Setting the scene Circuits can contain one loop (series circuit) or more than one loop (parallel circuit). You have already investigated current and potential difference in series circuits.A resistor is a component that reduces the limits the current flow in a circuit. You can get resistors with different resistances. This is the circuit symbol for a resistor:

AimsIn this practical you will: compare the drop in potential difference across resistors connected in

series and in parallel compare current in series and parallel circuits.

You will be using enquiry processes to: Enquire: select, plan and carry out the most appropriate types of

scientific enquiries to test predictions, including identifying independent, dependent and control variables

Analyse: use data to look for patterns in current and potential difference Analyse: present observations and data, and draw conclusions Communicate: present explanations for data and observations.

HypothesisLook at the two circuit diagrams:

Identify the variables that you could change in the circuits above.

Use the student book and your knowledge from previous lessons to write a hypothesis for how you think the potential differences in the series circuit will be different from the potential differences in the parallel circuit.

Method1 Visit each experiment in turn, where you will find a different circuit set up for you.

Switch on the circuit.2 Write the current or potential difference readings on the diagrams. 3 Unscrew one bulb in each circuit and write down your observations below each

diagram. Remember to replace the bulb before leaving the station. 4 Switch the circuit off. Repeat at the next experiment until you have visited all four

circuits, and noted all results down.

Experiment 1: Current in a series circuit

Experiment 2: Potential difference in a series circuit

Experiment 3: Current in a parallel circuit

Experiment 4: Potential difference in a parallel circuit

Questions1 State one difference in the shape of a series circuit and a parallel circuit.

2 Describe the pattern shown in your results. Give examples. a current in series circuit

b current in parallel circuit

c potential difference in series circuit

d potential difference in parallel circuit

Extension1 Complete the following sentences using your knowledge about the number of paths

available in series and parallel circuits.Current is the same in all places in a series circuit because

Current is shared between branches of a parallel circuit because

2 Evaluate the accuracy of the data obtained in this experiment.(Hint: does your data match your answer in Extension Question 1 exactly? If not, why not?)

3 The lights in your house are all connected in one lighting circuit.Use your everyday observations and your knowledge of circuits to suggest whether the lights in the circuit are connected in series or in parallel. Explain your answer.

Lesson 8 - Investigating currentSetting the scene We can measure the current flowing through a circuit using an ammeter. If the circuit changes the current may change as well. You will compare and explain the current flowing in different parts of series and parallel circuits.

AimsIn this practical you will: set up series and parallel circuits measure current in series and parallel circuits.

You will be using enquiry processes to: Enquire: select, plan and carry out the most appropriate types of

scientific enquiries to test predictions, including identifying independent, dependent and control variables

Enquire: use suitable equipment to take measurements Analyse: present observations and data Analyse: draw conclusions from your results Communicate: present reasoned explanations and communicate your

ideas.

Safety Be careful when changing the circuit, as wires may be hot.

Equipment and materials battery pack connecting leads ammeter bulb motor buzzer switch

Method1 Set up circuit 1 as in the diagram below.

2 Measure the current and record the reading.State the function of the ammeter.

State the function of the switch in your experiment.

3 Add another bulb to the circuit to make circuit 2 as shown in the diagram.

4 Measure the current through each ammeter and record the readings.Describe what happened to the current when you added another bulb in series with the first one.

5 Set up the parallel circuit (circuit 3) as in the diagram.

6 Measure the current through each ammeter and record the readings.Describe what happened to the current at A1 and A4 when you added another bulb in parallel with the first one.

For circuit 3, compare the readings on A1 and A4 with the readings on A2 and A3.

Explain, in terms of current flow, why the readings on A1 and A4 are different from the readings on A2 and A3 in circuit 3.

Lesson 9 - ElectrostaticsSetting the scene When you comb your hair, take off a jumper, walk across a carpet, or touch a door handle, you may see sparks. These are caused by static electricity. You will learn more about static electricity in this activity.

Questions1 Name the two types of charge.

2 Describe how you can charge a balloon.

3 Describe the two possible effects a charged object can have on another charged object.

4 Give one example of the balloon repelling another object. Explain why the balloon repelled the object.

5 State what an electric field is.

6 Explain why a charged balloon will affect the motion of nearby objects but an uncharged balloon will not. Explain your answer in terms of electric fields.

Extension1 Explain how an object, for example, a balloon, can become charged. Use as many

scientific terms as possible in your answer. You must use the phrase electron transfer.

2 Tap water contains impurities that are charged. Predict how a balloon will affect a stream of tap water. Give a reason for your answer.

3 Compare how charged objects affect each other with how magnets affect each other.

1

Lesson 10

ACRI

NC

a What I is a magnetic material? ________________________

b What NC force is magnetism? ________________________

c What R and A are things that magnets can do to each other? ________________________________________________

d What C is the piece of iron inside an electromagnet? ________________________

2 The drawing shows bar magnets attracting and repelling each other. Fill in the missing letters on the magnets, and say whether each pair is attracting or repelling. One has been done for you.

3 The drawing shows an electromagnet.

a Write down one way of making an electromagnet stronger.

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b Write down two ways in which an electromagnet is different to a bar magnet. (Hint: Think about what they are made from and how they work.)

i ________________________________________________________________________

ii ________________________________________________________________________

Use these cards to help you to summarise what you know about magnets and magnetic fields.

Magnetic questions

S N

S N

S N

N S

N S repel_________________

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Key facts cards

I CAN...

I can summarise what I know about magnets and magnetic fields.

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Key questions on Electricity & magnetism unit

attract magnetic northrepel south

field magnetic space direction

compass Earth field north coils core currentelectromagnet stronger

Key Question 1: Label this diagram of an atom.

Key Question 2: State the charges on an electron and a proton.

Key Question 3: Explain why rubbing a balloon on your head causes static electricity.

Key Question 1: Draw the symbol for a bulb.

Key Question 2: Predict whether the bulb will be on in this circuit and explain your prediction.

Key Question 3: Explain the difference between a series and a parallel circuit

Key Question 1: Describe how current is measured and what the units are.

Key Question 2: Define ‘current’.

Key Question 3: Describe what happens to current when more bulbs are added to a circuit.

Key Question 1: In the rope model of electricity, what does the rope represent?

Key Question 2: Explain why someone gripping the rope tighter represents a bulb.

Key Question 3: Explain why adding a bulb in a circuit decreases the current.

Key Question 1: How is potential difference measured and what are the units?

Key Question 2: What does the potential difference of a battery tell you?

Key Question 3: Predict the potential difference of the cell in this circuit.

Key Question 1: Why are Christmas lights wired in a parallel circuit?

Key Question 2: Predict the potential difference of the cell in this circuit if V2 and V3 show 4 V.

Key Question 3: Explain how current and potential difference act differently in a series circuit.

Key Question 1: State one thing you can do to work well as a team.

Key Question 2: Are precise results always the true result?

Key Question 3: Explain whether these results are precise or not.

Key Question 1: What is resistance and what units is it measured in?

Key Question 2: Calculate the resistance of a bulb that has a potential difference of 10 V and a current through it of 2 A.

Key Question 3: Does an insulator have a high or a low resistance? Explain your answer.

Key Question 1: What happens when two like and two unlike poles are placed near each other?

Key Question 2: How does a compass work?

Key Question 3: How can you find the magnetic field lines of a magnet?

Key Question 1: State a difference between an electromagnet and a permanent magnet.

Key Question 3: How does an electromagnet work?

Key Question 3: Describe how to make an electromagnet stronger.

Key Question 1: State a use for an electromagnet.

Key Question 2: Explain why electromagnets are ideal for moving scrap metal.

Key Question 3: Explain how a motor works.

Answers – Investigating potential differenceQuestions 1 Measure the potential difference, in volts, of a circuit. 2 For example, the voltmeter was connected in the circuit using two leads either

side of a component, making its own loop (in parallel to the component measured).

3 The potential difference increased when you used more cells because each cell supplied 1.5 V – so more energy was transferred.

4 The potential difference across each bulb was half the potential difference of the battery; the potential difference was the same for each bulb; the potential

difference across two bulbs added up to the potential difference across the battery.

5 The voltmeter readings would be negative but have the same value.Extension1 Potential difference must be measured in parallel because in a parallel circuit the

potential difference across each branch is the same as the potential difference across the battery.

2 Increasing the number of cells would increase the brightness of the bulbs as more energy is transferred.

3 Credit any sensible answers, for example, mains voltage is much larger than a power supply so more risks associated.

Answers - Investigating length of a wirePredictionAs the length of the wire increases, the resistance will increase.Questions1 a Three examples of insulators: for example, wood, plastic, and rubber.

Three examples of conductors: credit any three metals. Water and graphene also conduct electricity, so credit should be given if they are provided as examples but students are unlikely to know this.

b Insulators will have a high resistance reading, whereas conductors will have a low resistance reading.

2 Graphs should show a straight line showing resistance doubles as length doubles. Credit uses of numerical data in their descriptions.

3 The measurements of resistance are much higher if an insulator is used.4 Resistance measures how hard it is for current to flow in a circuit.

5 ab resistance = 6 V/2 A = 3 Ω

Extension1 Resistance is caused by materials not having many electrons that are free to

move. Credit any two sensible suggestions.

2 a For example, enough readings are needed to show a pattern; tried to use the whole length of wire available; it was easy to measure.

b This will be dependent on the student’s procedure. Their discussion should include explanations of any points they make. Credit a sensible suggestion for improvement of the method.

Answers – Series and Parallel circuitsQuestions 1 A series circuit has one loop and a parallel circuit has several loops.2 Answers depend on data so credit answers that use data or refer to ammeter or

voltmeter readings. a Current in series circuit is the same throughout the circuit.b Current in branches of a parallel circuit adds up to current from the cell.c Potential difference in series circuit is shared between components.d Potential difference in parallel circuit is the same in all branches.

Extension1 there is only one path.

there are several paths; it splits to go through different branches, and rejoins to return to the cell.

2 Depends on results but often the pattern is roughly as described in Question 1. Possible reasons why the data may not be exact include: the effect of connecting leads; bulbs not being exactly the same; parts of the circuit warming up.3 Lights in a house can be switched on independently. A ring main is a parallel

circuit.

Answers – Investigating currentQuestionsThe questions are given throughout the method.1 To measure current.2 To turn the circuit/current on or off.3 The current decreased. 4 The current increased at A1 and A4. 5 The currents at A2 and A3 were approximately half the current at A1/A4.6 A1 and A4 measure the total current in the circuit. The currents in the branches (A2

and A3) of a parallel circuit add together to make the total current. A1 = A4 = A2 + A3

Extension1 Adding a third bulb to circuit 2 would make the current through each bulb decrease.

Adding a third bulb to circuit 3 would make the total current increase but the current in each branch would stay the same.

2 Ammeter reading should not change because current stays the same around a series circuit. This is because there is only one path for electrons to flow around a series circuit.

Answers – ElectrostaticsTask1 Charged balloon on hair – hair attracted to the balloon.2 Rubbed balloon on small pieces of paper – pieces of paper attracted to the

balloon.3 Balloon rubbed on hair – hairs repelled each other.4 Balloon rubbed on a jumper and brought close to a pepperoni sausage suspended

with thread – pepperoni sausage rotated and attracted by the charged balloon.5 Two balloons rubbed on a jumper and tied to some thread. One balloon suspended

by the thread and the other held near – the balloons repelled each other.Questions1 positive and negative2 Charge the balloon by rubbing it on an insulator, for example, hair. Note that you

cannot charge one balloon by rubbing it on another balloon. 3 attract (e.g., paper) or repel (e.g., another balloon)4 Credit any sensible suggestion, for example, another balloon. These repel as they

have the same charge.5 An electric field is the region surrounding a charged object where other charged

objects will feel a force.6 The charged balloon affects nearby objects because it is surrounded by an electric

field but an uncharged balloon does not have a surrounding electric field.Extension1 An object, such as a balloon, can become charged by friction with an insulator.

Electrons are transferred by friction from the insulator to the object, or vice versa. The direction of electron movement can be predicted using the triboelectric series. The object that loses electrons will become positive; the object that gains electrons will become negative.

2 A balloon makes a stream of water change direction. This is because both the balloon and water are charged. Like charges repel, opposite charges attract.

3 Charged objects and magnets can both attract and repel other charged objects and magnets.

Answers to Key question – Electricity and Magnetism

Key Question 1: Label this diagram of an atom.Expected answer: A – electronB – neutron

C - protonKey Question 2: State the charges on an electron and a proton.Expected answer: Electron = negative chargeProton = positive chargeKey Question 3: Explain why rubbing a balloon on your head causes static electricity.Expected answer:- Electrons transfer from your head to balloon- Balloon has a negative charge- Your head has a positive charge- So the balloon and your head are attracted to each other

Key Question 1: Draw the symbol for a bulb.Expected answer: Key Question 2: Predict whether the bulb will be on in this circuit and explain your prediction.Expected answer:No – because the switch is openNo – because the circuit is incomplete Key Question 3: Explain the difference between a series and a parallel circuitExpected answer:Series – there is only one route electricity can flow throughParallel – there are difference routes electricity can flow through. Has branches.

Key Question 1: Describe how current is measured and what the units are.Expected answer:Current is measured by adding an ammeter to the circuit.Current is measured in amps.Key Question 2: Define ‘current’.Expected answer:Current is the amount of electric charge flowing around a circuit. Key Question 3: Describe what happens to current when more bulbs are added to a circuit.Expected answer:Current decreases when more bulbs are added.

Key Question 1: In the rope model of electricity, what does the rope represent?Expected answer:Electrons / charge free to move in the wire.Key Question 2: Explain why someone gripping the rope tighter represents a bulb.Expected answer:Bulbs have resistance / slow down electrons so gripping the rope tighter imitates this (by slowing the rope’s movement).Key Question 3: Explain why adding a bulb in a circuit decreases the current.Expected answer:Bulbs cause resistance because electrons slow down as they pass through the very thin metal filament.This causes current to slow down.

Key Question 1: How is potential difference measured and what are the units?Expected answer:Use a voltmeter and the units are volts.Key Question 2: What does the potential difference of a battery tell you?Expected answer:The difference in electrical energy either side of the battery.It also tells you how much energy can be transferred to components.Key Question 3: Predict the potential difference of the cell in this circuit.Expected answer:10 V

Key Question 1: Why are Christmas lights wired in a parallel circuit?Expected answer:If one bulb breaks then the rest stay on.Key Question 2: Predict the potential difference of the cell in this circuit if V2 and V3 show 4 V.Expected answer:4 VKey Question 3: Explain how current and potential difference act differently in a series circuit.Expected answer:Current is the same everywhere in a series circuit, whereas p.d. of the cell is shared between components.

Key Question 1: State one thing you can do to work well as a team.Give each person a job Give helpful feedbackListen to each other speakShow empathy to each other. ‘Put yourself in their shoes’Key Question 2: Are precise results always the true result?Expected answer: No, precise just means the results are close to the mean value, they could be true or false.Key Question 3: Explain whether these results are precise or not.Expected answer: Yes they are precise because they are close to the mean value.

Key Question 1: What is resistance and what units is it measured in?Expected answer:When it is difficult for electrons/charge/current to pass through a component.Ohms (Ω)Key Question 2: Calculate the resistance of a bulb that has a potential difference of 10 V and a current through it of 2 A.Expected answer:Resistance = potential difference ÷ currentResistance = 10 ÷ 2Resistance = 5 ΩKey Question 3: Does an insulator have a high or a low resistance? Explain your answer.Expected answer:Insulators have a very high resistance.Insulators do not allow electrons/charge/current to pass through easily.This is because insulators do not have free, moving electrons.

Key Question 1: What happens when two like and two unlike poles are placed near each other?Expected answer:Like poles repelUnlike poles attractKey Question 2: How does a compass work?Expected answer:By having a tiny magnetic metal strip that is free to move and lines up with the Earth’s magnetic field so it points to north.Key Question 3: How can you find the magnetic field lines of a magnet?Expected answer:Use a small compass, place it around the magnet and record where north is pointing each time.Shake iron filings over paper with a magnet underneath

Key Question 1: State a difference between an electromagnet and a permanent magnet.Expected answer:You can turn off an electromagnet but cannot turn off a permanent magnetElectromagnets need electricity and a solenoid to work, permanent magnets do notElectromagnets can be made much stronger than permanent magnetsKey Question 2: How does an electromagnet work?Expected answer:A coil of wire with current flowing through it has a magnetic field.Many coils around a magnetic core have a strong magnetic field.Key Question 3: Describe how to make an electromagnet stronger.Expected answer:More coilsIncrease the currentUse a magnetic metal as the core (iron, nickel, cobalt)

Key Question 1: State a use for an electromagnet.Expected answer:Motor, start engine, levitate trains, bell, circuit breakersKey Question 2: Explain why electromagnets are ideal for moving scrap metal.Expected answer:Can turn off and onCan change the strength of the magnet for lifting different thingsKey Question 3: Explain how a motor works.Expected answer:When a electromagnet is placed near a permanent magnet it is repelled and attracted to it causing it to rotate

Key Question 1: Why is using models useful to understand science?Expected answer: In science, a model is a representation of an idea, an object or a process that is used to describe and explain something that cannot be experienced directlyKey Question 2: What part of the crayon model represents the melting of rock to form magma?Expected answer: When the crayon is placed in foil, on hot water until it melts into a liquidKey Question 3: Explain one way that the crayon model is different to the real rock cycle.Expected answer: any one from:- Weathering is caused by wind and water in the rock cycle- Crayons have a lower melting point than rock- There is pressure applied in the formation of metamorphic rock in the rock cycle- The model works fast but the rock cycle takes millions of years