Contents COMUNICATION AND CRITICAL SPIRIT COMPETENCES AND MULTIPLE INTELLIGENCES LESSON PAGE VALUES. 1. Matter

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1 ok o b s t n e Stud l a r u t a N e c n e i c S 6

2 Contents LESSON PAGE VALUES COMUNICATION AND CRITICAL SPIRIT COMPETENCES AND MULTIPLE INTELLIGENCES 1. Matter 4 to 23 Learning to recycle organic waste. Explaining the effects of forces on every day actions. Mathematical competence and basic competence in science and technology / Logical-mathematical 2. Energy 24 to 47 Understanding the risks of noise pollution and how to prevent them. Explaining the phenomena related to the reflection of sound. Mathematical competence and basic competence in science and technology / Visual-spatial 3. Plants are living things 48 to 69 Learning how to prevent forest fires. Explaining how bacteria can be useful or harmful. Learning to learn / Naturalistic 4. The animal kingdom 70 to 93 Learning about endangered species. Learning which are my strongest skills. Sense of initiative and entrepreneurship / Interpersonal 5. Nutrition 94 to 109 Adopting a healthy and balanced diet. Explaining how the body absorbs nutrients. Digital competence / Intrapersonal 6. Sensitivity and reproduction 110 to 133 Understanding the effects of alcohol, tobacco and drugs. Interviewing my classmates about their healthy habits. Social and civic competence / Interpersonal

3 I HAVE LEARNT Read Speak Talk Write Listen I can read about the properties of matter. I can name some examples of pure substances and mixtures. I can describe the composition and the states of matter. I can write about the methods and instruments used to separate mixtures. I can listen and understand vocabulary about chemical reactions. I can read about renewable and non-renewable sources of energy. I can name the main components of an electrical circuit. I can talk about how light behaves when hitting an object. I can write about how machines make our life easier. I can listen to my classmates talking about the uses of magnets. I can read about cells and life processes. I can name some examples of microbes. I can talk about the function of each of the parts of a plant. I can write about the characteristics of the main groups of plants. I can listen to my teacher talking about viruses and vaccines. I can read about the adaptation of animals to their habitats. I can name the main groups of vertebrates and invertebrates. I can explain the main characteristics of each group of animals. I can describe the relationships within a food web. I can listen to a CD track about the characteristics of mammals. I can read about the process of breathing. I can name the parts of the circulatory system and the heart. I can talk about the excretion of waste substances. I can write about the properties and nutrients that each type of food has. I can listen to a CD track about inhalation and exhalation. I can read about the nervous system and its parts. I can name the main bones and muscles in the body. I can talk about puberty and the changes it produces. I can write about pregnancy an birth. I can listen to my classmates talking about healthy habits.

4 n o s s e L 1 r e t t a M Look and think: Everything around us is made up of matter. Matter is present in three different states: solids, liquids and gases. Each of them has a different structure and behaves differently. Different types of matter often mix together and form mixtures. Do you know why hot air balloons go up? 4 four

5 What is matter made of? Solids, liquids and gases are all made of matter. All matter is made up of very tiny components called atoms. Atoms are the smallest possible units of matter, and cannot be broken down into smaller units. Small groups of atoms combine into molecules, which are also very small. Objects are made up of millions of molecules. ATOMS AND MOLECULES Atoms can combine in many different ways to create different types of matter. For example, water is made up of atoms of hydrogen and oxygen. When two atoms of hydrogen combine with one atom of oxygen, a molecule of water is created. STATES OF MATTER Matter is present in nature in three different states: solid, liquid or gas. Sometimes matter can change states when exposed to physical processes. SOLIDS LIQUIDS GASES Molecules are very close together. Molecules are not so close together. Molecules are further apart. Watch a video about atoms! What happens to the shape of solids, liquids and gases when you put them into a container? 1. Which is bigger, an atom or a molecule? Explain. 2. How can matter change states? Can you think of any examples? 3. Write down the names of three solids, three liquids and three gases. five 5

6 General properties of matter General properties are those that depend on the amount of matter that is present. They are common to all matter. Mass, volume, size and weight are the general characteristics of matter. On the other hand, specific properties vary from one type of matter to another: colour, hardness, flexibility, conductivity... Let s have a look at how mass and volume are measured. MEASURING MASS Mass is the amount of matter contained in one object. Mass and weight are not the same thing. But generally speaking, objects with more mass also have a greater weight. We use the following units to express mass: 1 kilo (kg) 1,000 grams (g) 1,000 kilo (kg) 1 tonne (t) = = The amount of matter that a watermelon has is greater than that of an apple. The watermelon s mass is greater. Mass is measured with scales. These can be digital or mechanical. DIGITAL SCALES MECHANICAL SCALES Digital scales are electronic. They are very precise and show the mass on a screen. We can also use mechanical scales, but they are less precise.. 6 six 1. Do you have scales at home? What kind are they? What do you use them for? 2. Which objects would you measure in grams? Which would you measure in kilos and tonnes? 1. Would you use digital or mechanical scales to measure the mass of a spoonful of sugar? Why? 2. Convert these into grams: 2.76 kg 1.29 t 3. Why do we say that mass is a general property of matter?

7 MEASURING VOLUME Volume is the space that one object occupies. It is not always directly related to mass. We use the following units to express volume: This rock has a greater mass than the balloon, but the balloon occupies more space. Therefore, the balloon has a greater volume. = 1 litre (L) 1,000 millilitres (ml) = 1 millilitre (ml) 1 cubic centimetre (cm 3 ) We use graduated cylinders to measure the volume of liquids. But we can also use them to measure the volume of solids. MEASURING LIQUIDS MEASURING SOLIDS Graduated cylinders come with marks to measure volume. In this case, we have 300 ml of liquid. We can measure the volume of a solid by putting it into a liquid and calculating the difference in volume. In this case, 500 ml 300 ml = 200 ml = 200 cm 3. Watch a video about mass and volume! 1. Which has a greater mass: a kilo of wood or a kilo of air? Which has a greater volume? Why? 2. Explain in your own words how we would measure the volume of the following: coffee a small rock seven 7

8 Specific properties of matter: density and buoyancy A substance or object has more density when its molecules are closer together. This means that generally speaking, solids are denser than liquids, and liquids are denser than gases. But different solids, liquids and gases also have different densities. Density is calculated by dividing the mass by the volume. It is measured in grams per cubic centimetre (g/cm 3 ). MEASURING DENSITY These blocks of iron and cork have the same volume. But iron has its molecules closer together than cork. Therefore, iron has more density. If we divide the mass of each block by its volume, we can see that iron is denser than cork. Density is a specific property of matter. This means that each material has a certain density, regardless of its amount. For example, these two blocks of iron have different masses and volumes, but since they re made of the same substance (iron) they have the same density. Mass: 16 g Volume: 2 cm 3 Density: 16 / 2 = 8 g/cm 3 Mass: 1 g Volume: 2 cm 3 Density: 1 / 2 = 0,5 g/cm 3 Density does not depend on the mass or the quantity of matter: iron always has the same density. We can observe one of the effects of density in the atmosphere. Hot air is less dense than cold air. As a consequence, it moves upwards and sits on top of the cold air. Fact! Osmium is the densest known substance. It s 22 times denser than water! 8 eight Do you remember why wind occurs? How is that related to density? Look at the density of some common substances! pgxw8

9 BUOYANCY Some objects float when we put them in a liquid. Others sink. The ability to float is called buoyancy. Have you ever wondered why buoyancy occurs? Rocks don t float because they re denser than water. Driftwood floats because wood, even when it s a solid, is less dense than water. When the density of an object is lower than the density of water, it floats. When the density of an object is greater than the density of water, it sinks. But how can objects that are denser than water still float? Glass is denser than water, but this bottle is full of air. The density of the air combined with the density of the glass is lower than that of water. Large boats can also float because they re full of air. 1. What happens when you put water and oil in the same container? Why? 2. Put these in order from the densest to least dense: air water lead oil iron glass 3. Can the density of iron change sometimes? Why? 4. The mass of object A is 56 grams, and it occupies 7 cm 3. The mass of object B is 256 grams, and its volume is 128 cm 3. Which of them is denser? nine 9

10 Other specific properties of matter Matter has other specific properties that make some materials useful for certain purposes. For example, we use iron or steel to make tools because those metals are strong. We use diamond to cut through glass because it s hard. Other materials are very useful for making complex machines or electric appliances because they are able to conduct heat and electricity. CONDUCTORS OF HEAT Conductors of heat are materials that allow heat to travel through them easily. All metals are good conductors of heat. We use metal to make objects that we want to heat up. CONDUCTORS OF ELECTRICITY Conductors of electricity let electricity travel through them. Metals and water are some examples. Electric cables are made of copper because copper conducts electricity and it s also flexible. INSULATORS OF HEAT Insulators of heat do not let heat travel through them. Plastics, wood and some fabrics are insulators of heat. This pot has a plastic handle so that we can hold it without burning ourselves. INSULATORS OF ELECTRICITY Insulators of electricity do not let electricity travel through them. Plastics, rubber, glass... are some examples. Copper wires are covered in plastic so we can handle them safely. What other specific properties of matter do you know? Do you remember any examples of materials with these properties? Read more about electric conductivity! 1. What materials are these made of? Are they conductors or insulators? 2. Research, make a chart and write down some examples of conductors and insulators of heat and electricity. 10 ten

11 Effects of forces on matter A force is an action (usually a pull or a push) that can produce effects on matter. Forces are present in many aspects of our daily lives, and although we cannot see them, we can easily observe their effects on the objects that surround us. CHANGES OF SHAPE Forces can alter the shape of an object in different ways: Forces Applying force with a sharp object can cut some objects. If an object is fragile, it can be broken with little force. Force can also deform some objects. If the object is not flexible (like a can of soft drink), it will deform permanently. If the object is flexible (like a spring), it will go back to its original shape when the force is released. MOVEMENT AND CHANGES OF DIRECTION Forces can also produce movement: Wind Wind A force can make an object start moving......accelerate......change direction......slow down (decelerate)......and stop. What other materials can we easily deform with our hands? Do they go back to their original shape? 1. How do catapults work? Do they produce movement? What happens to their elastic band? 2. Write down three examples of materials that can easily be broken. eleven 11

12 Pure substances and mixtures You already know that matter can be classified as solid, liquid or gas. But there are other ways to classify matter. Pure substances are those made up of only one type of matter. This means that pure substances have only one type of molecule. Mixtures, on the other hand, are made up of several types of matter. Therefore, they have several types of molecules. PURE SUBSTANCES A pure substance cannot be separated into two or more substances by physical means. Pure substances are homogeneous. Some examples are: Solids: metals like gold, silver, iron or lithium are pure substances. So minerals like salt or diamonds (which are made of carbon, which is also a pure substance). Gases: oxygen, nitrogen, hydrogen... Liquids: pure water is a pure substance. All molecules of water are identical. Mercury is a liquid metal which is also a pure substance. MIXTURES Mixtures are made up of several substances. Therefore, they can be separated into different components. For example: This rock is made up of two minerals of different colours. Soft drinks are made up of several ingredients mixed together. Fact! Most of the things that we have around us are mixtures. 1. Why do we say that pure substances are homogeneous? 2. What other mixtures can you think of? What components are in them? 12 twelve

13 There are heterogeneous and homogeneous mixtures: HETEROGENEOUS MIXTURES In heterogeneous mixtures, we can easily see the different components that make up the mixture. Salads are made up of several vegetables, oil, vinegar, salt... Soil is a mixture of very small rocks, organic matter and chemicals such as oxygen and nitrogen. TYPES OF MIXTURES HOMOGENEOUS MIXTURES In homogeneous mixtures, we cannot see the different components that make up the mixture. The most abundant substance is called solvent, and the substance that is dissolved into the solvent is the solute. ALLOYS Alloys are homogeneous mixtures in which at least one of the components is a metal. 1 Chocolate cookies are made up of cookie dough and bits of chocolate. Listen and classify these pure substances, heterogeneous mixtures, homogeneous mixtures and solutions. Steel is an alloy of iron and carbon. SOLUTIONS Bronze is an alloy of copper and tin. Usually, homogeneous mixtures are found in a liquid state. These are called solutions. For example, saltwater is a solution of water and salt. In this case, water is the solvent and salt is the solute. 1. Write down five pure substances and five mixtures and explain what type of mixtures they are. 2. Explain what a pure substance is. 3. What kind of mixture is instant hot chocolate? Can you identify its components? 4. Are all metals pure substances? Explain. thirteen 13

14 Separating heterogeneous mixtures There are several ways of separating heterogeneous mixtures using special laboratory equipment. We choose a method depending on the characteristics of the mixture. Decantation, magnetism, sieving and filtration are some of these techniques. DECANTATION Decantation allows us to separate mixtures in which the components of a heterogeneous mixture have different densities. For example, two liquids, or one insoluble solid and one liquid. 1. First, we have to wait until the mixture settles. In this case, the oil sits on top of the water because its density is lower. 2. We start pouring carefully into a second container. MAGNETISM 3. Once we have finished pouring the oil, we have one container with oil and another one with water. We can use magnets to separate mixtures in which one of the components is a metal that can be attracted by a magnet and the other isn t. If we have a mixture of wood chips and iron filings, we can take out the iron with a magnet. SIEVING Sieving is a very useful method to separate mixtures of solids in which the components have particles of different sizes. 1. We start by putting a mixture of small rocks and sand in the sieve. 2. When we shake it, the sand goes through the sieve and the rocks don t. 3. Once we finish sieving, we have all the rocks in the sieve and all the sand on the table. 14 fourteen

15 FILTRATION Filtration allows us to separate mixtures in which one of the components can be caught in a filter. We can use filtration to separate an insoluble solid from a liquid. Filters are usually made of a special type of paper that does not break when wet. 1. We pour a mixture of water and sand through the filter. 2. The filter catches the sand and the water falls into the container. Gold diggers use sieves to find gold in rivers. Fact! 2 Watch a video about decantation. 1. Do we use any of these techniques at home? When? 1. What methods would you use to separate these mixtures? Gasoline and water Screws and sand Noodle soup Sand and wood chips 2. What instruments do we need to perform these methods of separation of mixtures? Filtration Sieving Magnetism Decantation 3. Find some examples of these instruments in your household. Who uses them? What do they use them for? fifteen 15

16 Separating homogeneous mixtures Some techniques allow us to separate the different components that make up some homogeneous mixtures. Evaporation, crystallization and distillation are some of these techniques. EVAPORATION By heating a mixture until one of the substances evaporates, we can separate two liquids or separate a soluble solid from a liquid. This method is used, for example, to elaborate stock cubes by boiling broth. 1. If we want to separate the components that make up a solution, we heat it until the liquid evaporates. For example, if we heat a mixture of water and salt, the water will evaporate. 2. When the water reaches 100ºC, it evaporates (turns into gas) and we re left with the salt. CRYSTALLIZATION Crystallization is very similar to evaporation, but in this case we do not heat up the mixture. Instead, we just leave the mixture at room temperature for a longer period of time until the liquid has evaporated. 1. If we leave the same solution of water and salt in a container, water will very slowly evaporate. 2. The higher the temperature of the air, the faster the water will evaporate. Once it has evaporated, we re left with the salt. 16 sixteen

17 DISTILLATION Distillation allows us to separate liquids or solutions but with the advantage of catching the liquids again after they evaporate. Distillation is based on the fact that different liquids have different boiling points. This technique is used to make alcoholic beverages, perfumes and some fuels such as diesel and petrol. 1. First of all, we heat up the mixture. 2. The liquid with the lower boiling point evaporates. The vapour then goes through a pipe where it cools down and condenses into a liquid again. 3. The condensed liquid then falls into a container. Fact! Distillation was introduced into Europe by the Arabs during the Middle Ages. Think about the three methods of separating a solution of water and salt. Which method allows us to keep both components? In which methods do we lose one of the components? Which component do we lose? Watch how a mixture of alcohol and water is distilled at the laboratory! 1. Alcohol boils at 78.5 ºC. Water boils at 100 ºC. Explain how we would separate a solution of alcohol and water using a distiller. 2. What methods are used to obtain these products? Marine salt Chicken stock cubes Cologne seventeen 17

18 Chemical reactions Molecules of different kinds of matter can combine and create new matter. This is known as a chemical change or chemical reaction. As a result, a new substance is created. Usually a chemical reaction cannot be reversed. Chemical reactions happen, for instance, when we digest our food and turn it into nutrients. Or when plants transform water and carbon dioxide into their food. But there are more examples: DECOMPOSITION Decomposition is a process carried out by small organisms called decomposers. Decomposers break down dead organic matter and turn it into other substances. Fungi, worms and bacteria are examples of decomposers. Decomposition can be used to make compost, which is a type of fertiliser used in agriculture and gardening. Yoghurt is made by adding bacteria to milk. FERMENTATION Fermentation is a process carried out by certain types of bacteria and fungi. In fact, it is part of their nutrition: they transform some organic substances into other substances and their organsim obtains energy. During fermentation, sugar is converted into acid, gas or alcohol. We use fermentation to make yoghurt (the sugar in the milk is turned into acid when we add bacteria), bread (the sugar in the dough is turned into bubbles, which make the bread softer) or wine (the sugar in the grape juice is turned into alcohol). 18 eighteen

19 COMBUSTION Combustion occurs when a substance (known as fuel) burns when it is heated a lot and is in contact with another substance known as oxidant. As a result, new substances are created. If we apply a lot of heat to a fuel (wood) that is in contact with an oxidant (oxygen), it will burn. As a result of the combustion of wood, carbon dioxide is released and new substances (ash and smoke) are created. OXIDATION Oxidation is a very slow chemical process. Some metals, when in contact with the oxygen of the air or the water, oxidise and a new substance is created (rust). Iron reacts with the oxygen in the air and creates rust. Oxidation is not immediate. It takes a long time. The application of chemical changes in industry allows new materials with special properties to be created, such as heat insulation fabrics, that are used to make fire suits. Our heritage Compost can be made from recycling our organic rubbish. That s another reason to separate and recycle our waste! Do you separate and recycle your waste? Why should we do it? 1. Are decomposition, fermentation, combustion and oxidation reversible? Explain. nineteen 19

20 Activities 1. Draw one solid, one liquid and one gas. Make a diagram showing how close together their molecules are. 2. What do we use this equipment for? Digital scales Graduated cylinder Sieve Distiller Filter 3. Which of these has a greater mass? Which has a greater volume? Why is that? 4. Which of these objects float? Why? Silver earrings Cork A piece of plastic A piece of glass A bottle made of glass 5. Which of these materials conduct heat and electricity? Copper Iron Glass Water Rubber Wood Plastic Cotton fabric 6. Do you think that anything that you have learnt in this lesson could be useful for your daily life? Explain. 7. Write down three products that we make using chemical reactions. 8. Explain how forces affect the movement of a football during a game. 20 twenty

21 9. Work in pairs. Try to mix or dissolve some salt, some oil and some sand in water Take pictures of the different components before and after mixing. Write down the results and explain what methods you would use to separate them. Salt Oil Sand or earth Water 10. Make a chart like this and fill it in with some examples. PURE SUBSTANCES HOMOGENEOUS MIXTURES HETEROGENEOUS MIXTURES 11. Do this crossword. Group of atoms Most abundant substance in a solution Least abundant substance in a solution Metallic homogeneous mixture Material that lets heat or electricity travel easily twenty-one 21

22 Glossary Alter (verb): to change; to modify. Beverage (noun): drink. Boiling point (noun): the temperature at which a substance evaporates. Broth (noun): the water in which meat or vegetables have been boiled. Conduct (verb): to transmit. Decant (verb): to pour a liquid from one container to another. Dough (noun): a mixture of flour and water used for baking bread or pastries. Fertiliser (noun): any substance that helps plants grow; plant food. Filing (noun): a small particle removed by a file. Heterogeneous (adjective): consisting of dissimilar elements or parts. Homogeneous (adjective): consisting of parts that are the same. Regardless of (adverb): without reference to. Reverse (verb): to turn backwards. Fill in the gaps Complete the following statements: 1. All matter is made up of. 2. Each pure substance has only one type of. 3. Mass and volume are properties of matter. 4. Density, buoyancy and conductivity are properties of matter. 5. All metals are good. 6. can change the shape of an object, break it or make it move. 7. Deceleration is the opposite of. 8. In mixtures, we can easily see their different components. 9. Alloys and solutions are examples of mixtures. 10. We can separate mixtures of elements with different sizes with a. 11. Perfumes and gasoline are made by. 12. is a very slow chemical reaction. It occurs when metals are in contact with. 22 twenty-two

23 Diagrams Copy and complete the information in this chart: In groups, prepare a small presentation about matter and show your classmates what you learned in this lesson. Follow this chart to organise the information and prepare visual info such as photographs, murals or a power point to complete your presentation. PURE SUBSTANCES They... decomposed. They are made up of.... DECANTATION MATTER Can be separated by is made up of... We... their components. HETEROGENEOUS Can be separated by They are made up of.... We... their components. twenty-three 23