Science6Natural

Student’s book

Contents

LESSON

1. Matter

2. Energy

3. Plants are living things

4. The animal kingdom

5. Nutrition

6. Sensitivity and reproduction

VALUES

Learning to recycleorganic waste.

Understanding therisks of noise pollution and how to prevent them.

Learning how to prevent forest fires.

Learning about endangeredspecies.

Adopting a healthyand balanced diet.

Understanding theeffects of alcohol, tobacco and drugs.

COMUNICATION AND CRITICAL SPIRIT

Explaining the effectsof forces on every day actions.

Explaining the phenomena related to the reflection of sound.

Explaining how bacteriacan be useful or harmful.

Learning which are my strongest skills.

Explaining how thebody absorbs nutrients.

Interviewing my classmates about their healthy habits.

COMPETENCES AND MULTIPLE INTELLIGENCES

Mathematical competenceand basic competence in science and technology/ Logical-mathematical

Mathematical competenceand basic competence in science and technology/ Visual-spatial

Learning to learn /Naturalistic

Sense of initiativeand entrepreneurship/ Interpersonal

Digital competence / Intrapersonal

Social and civic competence / Interpersonal

PAGE

4 to 23

24 to 47

48 to 69

70 to 93

94 to 109

110 to 133

Read

I can read about theproperties of matter.

I can read about renewable and non-renewablesources of energy.

I can read aboutcells and lifeprocesses.

I can read about theadaptation of animals to their habitats.

I can read about theprocess of breathing.

I can read about thenervous system andits parts.

Talk

I can describe thecomposition and thestates of matter.

I can talk about howlight behaves whenhitting an object.

I can talk about thefunction of each ofthe parts of a plant.

I can explain themain characteristicsof each group of animals.

I can talk about theexcretion of wastesubstances.

I can talk about puberty and thechanges it produces.

Speak

I can name someexamples of puresubstances and mixtures.

I can name the maincomponents of anelectrical circuit.

I can name someexamples of microbes.

I can name the maingroups of vertebratesand invertebrates.

I can name the partsof the circulatorysystem and the heart.

I can name the mainbones and musclesin the body.

Write

I can write about the methods and instruments used to separate mixtures.

I can write abouthow machines make our life easier.

I can write about the characteristics of the main groups of plants.

I can describe therelationships withina food web.

I can write about the properties and nutrients that each type of food has.

I can write aboutpregnancy an birth.

Listen

I can listen and understand vocabulary about chemical reactions.

I can listen to myclassmates talkingabout the uses ofmagnets.

I can listen to myteacher talking about viruses and vaccines.

I can listen to a CDtrack about the characteristics of mammals.

I can listen to a CDtrack about inhalation and exhalation.

I can listen to myclassmates talkingabout healthy habits.

I HAVE LEARNT

Lesson 1Matter

4 four

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?

five 5

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 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.

Matter is present in nature in three different states: solid, liquid or gas. Sometimes matter can change states when exposed to physical processes.

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.

What happens to the shape of solids, liquidsand gases when you put them into a container?

Watch a video about atoms! http://links.edebe.com/cctqt

What is matter made of?

ATOMS AND MOLECULES

STATES OF MATTER

SOLIDS LIQUIDS GASES

Molecules are very close together. Molecules are not so close together. Molecules are further apart.

6 six

1 kilo (kg) 1,000 grams (g)

1,000 kilo (kg) 1 tonne (t)

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:

Mass is measured with scales. These can be digital or mechanical.

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.

We can also use mechanical scales, but they are less precise..

Digital scales are electronic. They are very

precise and show the mass on a screen.

The amount of matter that a watermelon has is

greater than that of an apple. The watermelon’s

mass is greater.

=

=

General properties of matter

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?

DIGITAL SCALES MECHANICAL SCALES

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 t3. Why do we say that mass is a general property of matter?

MEASURING MASS

7seven

1. Which has a greater mass: a kilo of wood or a kilo ofair? Which has a greater volume? Why?2. Explain in your own words how we would measurethe volume of the following: coffee — a small rock

We use graduated cylinders to measure the volume of liquids. But we can also use them to measure the volume of solids.

Volume is the space that one object occupies. It is not always directly related to mass.

MEASURING VOLUME

Watch a video aboutmass and volume!http://links.edebe.com/zrjs

1 litre (L) 1,000 millilitres (ml)

1 millilitre (ml) 1 cubic centimetre (cm3)

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.

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 cm3.

MEASURING LIQUIDS MEASURING SOLIDS

8 eight

MEASURING DENSITY

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/cm3).

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.

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.

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.

Specific properties of matter: density and buoyancy

Look at the density of some common substances!http://links.edebe.com/pgxw8

Do you remember why wind occurs? How is that related to density?

Osmium is the densest known substance. It’s 22 times denser than water!

Fact!

Mass: 16 g

Volume: 2 cm3

Density: 16 / 2 = 8 g/cm3

Mass: 1 g

Volume: 2 cm3

Density: 1 / 2 = 0,5 g/cm3

Density does not depend on the mass or the quantity

of matter: iron always has the same density.

9nine

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 — glass3. Can the density of iron change sometimes? Why?4. The mass of object A is 56 grams, and it occupies 7 cm3. The mass of object B is 256 grams, and its volume is 128 cm3. Which of them is denser?

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?

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?

BUOYANCY

Driftwood floats because wood, even

when it’s a solid, is less dense than water.

Rocks don’t float because

they’re denser than water.

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.

10 ten

Other specific properties of matterMatter 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 are materials that allow heat to travel through them easily. All metals are good conductors of heat.

Insulators of heat do not let heat travel through them. Plastics, wood and some fabrics are insulators of heat.

Insulators of electricity do not let electricity travel through them. Plastics, rubber, glass... are some examples.

Conductors of electricity let electricity travel through them. Metals and water are some examples.

What other specific properties of matter do you know? Do you remember any examples ofmaterials with these properties?

Read more about electricconductivity!http://links.edebe.com/cbg8

1. What materials arethese made of? Are theyconductors or insulators?2. Research, make achart and write down someexamples of conductorsand insulators of heatand electricity.

CONDUCTORS OF HEAT CONDUCTORS OF ELECTRICITY

We use metal to

make objects that

we want to heat up.

This pot has a plastic handle

so that we can hold it

without burning ourselves.

Copper wires are covered in

plastic so we can handle

them safely.

Electric cables are made of

copper because copper con-

ducts electricity and it’s also

flexible.

INSULATORS OF HEAT INSULATORS OF ELECTRICITY

Effects of forces on matterA 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:

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.

Forces

MOVEMENT AND CHANGES OF DIRECTION

Forces can also produce movement:

11eleven

What other materialscan we easily deformwith our hands? Dothey go back to theiroriginal shape?

1. How do catapults work?Do they produce movement?What happens to their elastic band?2. Write down three examples ofmaterials that can easily be broken.

...accelerate... ...change direction......slow down

(decelerate)......and stop.A force can make an

object start moving...

Wind Wind

12 twelve

Pure substances and mixturesYou 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.

1. Why do we say that pure substances are homogeneous?2. What other mixtures can you think of? What components are in them?

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.

PURE SUBSTANCES

A pure substance cannot be separated into two or more substances by physical means. Pure substances are homogeneous. Some examples are:

MIXTURES

Most of the things that we have around us are mixtures.

Fact!

This rock is made up of two minerals of different colours.

Soft drinks are made up of several ingredients mixed together.

Mixtures are made up of several substances. Therefore, they can be separated into different components. For example:

13thirteen

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.

There are heterogeneous and homogeneous mixtures:

In heterogeneous mixtures, we can easily see the different components that make up the mixture.

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.

Usually, homogeneous mixtures are found in a liquid state. These are called solutions. For example, saltwater is a solution of water and salt.

TYPES OF MIXTURES

Listen and classify these pure substances, heterogeneous mixtures, homogeneous mixtures and solutions.

1

HETEROGENEOUS MIXTURES HOMOGENEOUS MIXTURES

ALLOYS

SOLUTIONS

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.

Steel is an alloy of

iron and carbon.

Bronze is an alloy

of copper and tin.

Chocolate cookies are made up of

cookie dough and bits of chocolate.

In this case, water is

the solvent and salt

is the solute.

Alloys are homogeneous mixtures in which at least one of the components is a metal.

Separating heterogeneous mixturesThere 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.

14 fourteen

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.

MAGNETISM

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.

3. Once we have finished pouring the oil,

we have one container with oil and another

one with water.

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.

SIEVING

15fifteen

1. What methods would you use to separate these mixtures?Gasoline and water — Screws and sand — Noodle soup — Sand and wood chips2. What instruments do we need to perform these methods of separation of mixtures?Filtration — Sieving — Magnetism — Decantation3. Find some examples of these instruments in your household. Who uses them? Whatdo they use them for?

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.

FILTRATION

Watch a video about decantation.

2

1. Do we use any of these techniques at home? When?

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!

Separating homogeneous mixturesSome techniques allow us to separate the different components that make up some homogeneous mixtures. Evaporation, crystallization and distillation are some of these techniques.

16 sixteen

EVAPORATION

CRYSTALLIZATION

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.

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 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.

1. If we leave the same solution of water and salt

in a container, water will very slowly evaporate.

2. When the water reaches 100ºC, it evaporates

(turns into gas) and we’re left with the salt.

2. The higher the temperature of the air, the faster the

water will evaporate. Once it has evaporated, we’re

left with the salt.

17seventeen

1. Alcohol boils at 78.5 ºC. Water boils at 100 ºC.Explain how we would separate a solution of alcoholand water using a distiller.2. What methods are used to obtain these products?Marine salt — Chicken stock cubes — Cologne

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.

DISTILLATION

Watch how a mixture of alcohol andwater is distilled at the laboratory!http://links.edebe.com/bj69Think 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?

1. First of all, we heat

up the mixture.

3. The condensed liquid then

falls into a container.

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.

Distillation was introduced into Europe by the Arabs during the Middle Ages.

Fact!

Chemical reactionsMolecules 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:

18 eighteen

DECOMPOSITION

FERMENTATION

Decomposition is a process carried out by small organisms called decomposers. Decomposers break down dead organic matter and turn it into other substances.

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).

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.

19nineteen

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.

COMBUSTION

If we apply a lot of heat to a fuel (wood) that is in

contact with an oxidant (oxygen), it will burn.

Iron reacts with the oxygen in

the air and creates rust.

As a result of the combustion of wood, carbon dioxide is

released and new substances (ash and smoke) are created.

Oxidation is not immediate.

It takes a long time.

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).

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.

OXIDATION

Compost can be made from recycling our organic rubbish. That’s another reason to separate and recycle our waste!

Our heritage

1. Are decomposition, fermentation, combustionand oxidation reversible? Explain.

Do you separate and recycle yourwaste? Why should we do it?

Activities

20 twenty

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.

21twenty-one

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.

10. Make a chart like this and fill it in with some examples.

11. Do this crossword.

Salt Sand or earthOil Water

PURE SUBSTANCESHOMOGENEOUS

MIXTURESHETEROGENEOUS

MIXTURES

Metallic homogeneous

mixture

Least abundant substance in a solution

Most abundant substance in a solution

Group of atoms

Material that

lets heat or

electricity travel

easily

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 incontact with ___________________________________ .

Fill in the gapsComplete the following statements:

22 twenty-two

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.

Glossary

Diagrams

23twenty-three

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.

MATTER

is made up of................

PURE SUBSTANCES

They are made up of................. .

They aremade up of................. .

We.......................

their components.

We.......................

their components.

Can beseparated

by

Can beseparated

by

HETEROGENEOUS

DECANTATION

They ........................ decomposed.