grade 6 -science

Student’s BookFirst Term

Science & You

Learn and Innovate

Si

xth Primary

6

Dear pupils:We are pleased to present this book (Science and you) which represents one of the cornerstones of the developed curriculum in science for sixth primary grade. This book achieves the curriculum development process to face the challanges of the twenty first century whose beginning goes in line with a competitive revolution in information and communication technology.

The curriwlum aims to achieve the following trends:

Enlightening you with the relationship between science and technology in the ��science field and its impact on development.

Ensurning the suitable situations that indicate the influence of scientific and ��technological progress in producing knowledge.

Focusing on your practice of reasonable and effective behavior towards using ��technological outputs.

Ensuring your acquistion of the scientific thinking methodology which enables ��you to move away from education based on recitation and pouring information to education based on self-learning merged with fun and excitement.

Focusing on your dependence on exploration to reach information and acquire ��more experiences, through improving basic thinking skills: observation, analysis, deduction and justification.

Providing you with opportunities to practice the roles of citizenship through ��self-learning methods, team work, negotiation, persuation, acceptance of the other opinion and avoidance of fanatism.

Working on your acquisition of life skills and management applied practical ��abilities through giving more concern to the practical and applied aspects.

This book consists of four units. Each unit includes integrated lessons that achieve ��the desired objectives of each unit.

We ask God Almighty that you gain advantage of this book. We pray Him that this book will be one of the cornerstones to be added to the love and belonging to Egypt.

Preparation Team

Introduction

Prepared ByMr. Mohamed Reda Ali Ibrahim

Dr. Mohamed Ahmed Abu Leila

Dr. Ahmed Reyadh El Sayed Hassan

All rights reserved no part of this bookmay be reproduced, stored in

a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying,

recording or otherwise,without prior written permission of the Publishers.

SAKKARAPublishing Company

5 Messaha Square - Al nada Building - Dokki - Giza.Tel.: 02/ 33357395

SAKKARAPUBLISHING COMPANY

�رشكة �سقارة للن�رش

Issued: 2010D.N: 8934/2010

ISPN: 978-977-706-002-8

Unit (3)

)The Atmosphere(

Lesson One Oxygen ....................................... p 38

Lesson Two Carbon Dioxide ..................... p 46 Lesson Three Nitrogen .................................... p 54

Unit (3) Test ............................................................ p 62

Unit (2)

)Thermal Energy(

Lesson One Heat Conduction ................. p 18

Lesson Two Measuring Temperature .... p 24

Unit (2) Test ............................................................ p 34

Unit (1)

)Force and Motion(

Lesson One Mass and Weight .................... p 2Unit (1) Test ............................................................ p 14

ContentsFirst Term

d

Unit (4)

(Structure and Function of the living Organisms)

Lesson One Human Nervous System .... p 66

Lesson Two Human Locomotory System ....p 76

Unit (4) Test ............................................................ p 84

General questions on science – first term ... p 86

e

Safety in Science Scientists know that they must work safely when doing experiments. You need to be careful when doing experiments too. Here are some safety tips to remember.

Safety Tips Read each experiment and activity carefully. ✔

Wear safety goggles when needed. ✔

Clean up spills right away. ✔

Never taste or smell substances unless directed to do so by your teacher. ✔

Handle sharp items carefully. ✔

Tape sharp edges of materials. ✔

Handle thermometers carefully. ✔

Use chemicals carefully. ✔

Dispose of chemicals properly. ✔

Put materials away you finish an experiment. ✔

Wash your hands throughly after each experiment. ✔

By the end of this unit, you should be able to:

Determine the weights of some �objects using the spring balance.

Compare between mass and weight. �

Unit Objectives

Mass and weight are two terms you often hear in your daily life when selling and buying. What is mass and weight? .... And other questions that we will try to answer in this unit.

Unit introduction

U n i t

U n i t

Un

itUn

it1Force and Motion

Lesson One

Mass and Weight

What can you see in this

�¹picture?

Record your observation.

�¹Share in discu

ssion with �¹your classmates and you

r

teacher.

2

Lesson One (1 - 1)UNIT

1

By the end of this lesson, you should be able to:

Determine the weights �of some objects using the spring scale.

Compare between mass �and weight.

Objectives

Mass and Weight

Net weight 5 kg

Fig (1 - 1): A flour bag

The confusion between mass and weight

is considered one of the most common

mistakes in our daily life especially what

is related to exchanging goods.

This is because the meanings of the two

terms become the same in one way or

another among people. Even the accurate

scientific explanation does not help people

to understand the real difference between

mass and weight.

Is the written statement on the flour

bag right? Why?

Mass

Weight

Basic concepts

3

(1-1

)First Term

Discover the concept of mass

Look at the following pictures and then answer the questions:��

Is the mass of 10 bananas equal to the mass 9 bananas? (Yes / No).��

Does the mass differ according to the amount of bananas? (Yes / No).��

Is mass of the matter in eggs equal to the matter of the searchlight? (Yes / No).��

In this exercise�� , we find that: the mass of bananas depends on its amount. This means that mass depends on the amount of matter. We also find that the mass of eggs is equal to the mass of the searchlight. This means they both contain two equal amounts of matter.

Ex

er

ci

se 10 bananas balance with 275 grams.

2 eggs balance with 120 grams.

9 bananas balance with 250 grams.

The searchlight balances with 120 grams.

Mass:�¹ the amount of matter in an object.

Mass is measured by gram or kilogram. �¹

The gram is equal to the mass of a paper clip whereas the kilogram is equal to a liter of water.

Fig (1 - 2): A group of objects of different masses.

Fig (1 - 3): A paper clip is equal to one gram.

Fig (1 - 4): A liter of water is equal to 1000 gram.

UNIT

1

4

Mass and weightMass and weight

Mass measurement:Different types of scales are used to measure the mass

such as: The balance scale and one-arm scale.

We should point out that the scale’s choice should match the amount of matter we need to measure its mass.

For example, the grocer’s balance cannot be used to measure the mass of gold and vice versa.

A balance scale

A one-arm scale with a pointer

A sensitive two-arm scale

A one-arm digital scale

There is a relation between mass and motion. The more an object's mass increases, the more difficult it is to change its speed. For example, the locomotive has bigger mass than the car, so the locomotive needs a stronger force to stop than what is needed for the car.

Enriching information

How do you measure the

mass?

Fig (1 - 5): Different types of scales

First Term

5

(1-1

)

How do we measure mass?Activity

What do you need? A balance scale, standard masses of the object we need to ��measure its mass.

What should you do?��

Put the balance scale on a stable ��

shelf horizontally to avoid any vibrations.Make sure that the balance scale ��

is clean in and out.Put the object on one of the arms.��

Put standard masses on the other ��

arm until the two arms balance.Add up the written numbers on the ��

standard masses. The total is the mass of the object.

We conclude that: �¹ The object mass is equal to the total mass of balance masses that are already known.

The object mass on the moon is 5 kg. The object mass on Earth is 5 kg.

Does mass differ from one place to another?After measuring the mass of an object on the Earth’s surface then measuring the mass

of the same object on the moon’s surface, we will notice that mass is not changed, i.e. mass of objects is stable and does not change from a place to another.

Fig (1 - 7): Object’s mass is constant and does not change from one place to another.

Fig (1 - 6): Two-arm scale with mass known weights

250 g

UNIT

1

6

Mass and weight

The concept of weight:

Discover the concept of weight

Look at the following pictures, and then answer the questions:��

Does the astronaut fall down when he jumps from a high position? (Yes / No).��

If the astronaut carries something and leaves it, will it fall down? (Yes / No).��

Does a person fall down when he jumps up on the Earth’s surface? (Yes / No).��

If you carry your pen and leave it while you are on the Earth’s surface, will ��

it fall down?

What makes objects fall downwards the Earth? �� .......................................................................

............................................................................................................................................................................................

The truth of objects’ falling downward the Earth means that there must be a ��force which pulls these objects down. You can feel this force if you carry an object or if you try lifting an object. This force is called “weight”.

Ex

er

ci

se

Weight:�¹ is the force with which a body is attracted to the Earth. This force is always towards the center of the Earth.

Weight is measured by �¹ Newton. Newton is almost equal to the weight of an object whose mass is 100 grams. For example, the gravitational force for a small apple (its mass is 100 grams) is equal to 1 Newton.

Fig (1 -8): Children on the Earth surface Fig (1 - 9): A astronaut inside a spacecraft

Fig (1 - 10): An apple.

First Term

7

(1-1

)

Measuring weightA weight of an object can be measured by the spring

balance through determining the distance a spring deflects under the object’s weight.

Factors that affect weightThe object is affected by three factors: the object

mass, the planet on which the object exists distance from the center of the planet. We will discuss these factors in details:

1 The object massThe object mass affects its weight. You can make sure

of this by doing the following activity:

How can weight be measured?

What do you need?�� A spring scale, an object


Hold the spring scale from its top hook. Then, ��

hang the object in the bottom hook. If you can not hang the object in the bottom hook, tie it with thread and then tie the thread in the bottom hook.Let the object go down slowly. You will notice ��

that the object pulls the spring downwards and the reading of the pointer increases. Wait until the object becomes stable and then read ��

the number which refers to how many Newton the down force is exerting and equal to the object weight.

What are the factors that affect

weight?

Activity Fig (1-11) The spring scale

Fig (1 - 12): How do you measure the weight?

123456789

Newton

UNIT

1

8

Mass and weight

Discover the relation between mass and weightActivity

What do you need? a normal scale, a spring scale, some objects different in ��mass.


Assign the first object’s mass using the normal scale.��

Assign the first object’s weight using the spring scale.��

Repeat the previous steps with the rest of the objects.��

Write down the results in a table.��

Suppose you got the following results��

5 4 3 2 1 The object’s mass

(kg)

50 40 30 20 10 The object’s weight

(Newton)

What is the relation between mass and weight?

We can conclude that the weight of an object on the surface of the Earth increases according to the increase in the object’s mass.

Weight (Newton)= mass (kg) x 10

First Term

9

(1-1

)

2 The planet where the object existsWeight differs according to the planet or (the moon) where

the object exists. The more the planet’s mass increases, the more the gravitational force and the more the object’s weight become. For example, on measuring an object’s weight on the surface of the Earth, and then measuring the same object on the surface of the moon, we notice that weight changes.

An object’s weight on the moon is equal to one sixths of its ��weight on Earth.

3 Distance from the center of the planet:An object’s weight is affected by the distance being away

from the center of the planet. The Earth gravitational force decreases as the body moves away from the Earth. We don’t usually notice this difference in weight because it is very little in such a case.

Comparison between mass and weight:

WeightMassPoint of

comparison

The force with which a body is attracted to the EarthThe amount of matter in an objectDefinition

NewtonKilogram or gramUnit of measurement

A spring scaleA balance scaleDevice of measurement

It is towards the center of the EarthHas no directiondirection

Changes from plant to anotherConstant (does not change with the change in place)

Effect of different places

Fig (1 - 13): The object’s weight on the Earth’s surface is equal to 6 Newton.

Fig (1 - 14): The object’s weight on the moon’s surface is equal to 1 Newton.

Fig (1 - 15): A balloon

UNIT

1

10

Mass and weight

Exercises1 Complete the following sentences:

a The measurement unit of mass is ….......….. or ….......….. whereas the measurement unit of weight is ….......…...

b Mass is measured by ….......….. whereas weight is measured by ….......…...

c Mass is a constant and is not affected by ….......…...

d An object’s weight depends on ….......…...

2 Write the scientific term:a The amount of matter in an object.

b The force with which a body is attracted to the Earth.

c The measurement unit of mass which is almost equal to a mass liter of water.

d The measurement unit of weight which is almost equal to a mass 100 grams.

3 An object whose mass on Earth is equal to 6 kg. Calculate its weight on both surfaces of the Earth and the moon.

4 The following pictures illustrate the steps of calculating a liquid mass using the digital scale. Look at the pictures and then calculate the mass and weight of this liquid.

Scale reading = 119.76 gm Scale reading = 186.73 gm

First Term

11

(1-1

)

5 Complete the following diagram.

.........

.........


.........

.........

Definition

.........

.........

Unit of measurement

.........

.........

Device of measurement

.........

.........

Effect direction

Mass

Weight

Write a research on the obstacles and the effects that ��face the astronauts because of weightlessness.

Research activity

Apply what you have learnt

Life applications

Have an interview with the school doctor about the ��dangers of extra weight on human’s health.

Aspects of health

Write an essay on the old and new ��measurement tools of mass and weight showing the different types of these tools and the effects of the progress of science and technology progress on the accuracy of these tools.

Technological applications

Write a research on the importance ��of measuring mass in daily life.

12

Design a simple model for a two-arm scale using ��simple tools such as: a ruler- a nail, yoghurt boxes, thread, cardboard, clay

Design a simple model for a spring scale using ��simple tools such as: rubber thread, yoghurt boxes, a nail, paper clips, stripe of cardboard, objects whose weights are known.

Making models

Mention the differences between the two-arm ��scale and the spring scale.

Is it possible to measure the mass of an object ��inside a spacecraft that revolves around the Earth? Why?

Critical thinking

13

UNIT

1

14

Unit (1) Test

1 Choose the right answer:a The device of measuring weight is ....................

1 one-arm scale. 2 two-arm scale. 3 digital scale. 4 spring scale

b An object whose weight is 20 Newton on earth, its mass is equal to ....................

1 10 kg. 2 2 kg. 3 200 kg. 4 20 kg.

2 Match from column (A) with the suitable term in column (B):

3 Complete the following sentences:a Mass is measured by ….......….. whereas weight is measured by ….......…...

b Mass is the amount of matter that body contains. It does not change according to ….......…...

c An object’s weight depends on ….......….., ….......….. and ….......…...

Unit (1) Test

(A)

Newton

Mass

Kg

Weight

Spring scale

(B)

The gravitational force for an object

The measurement unit of mass

The measurement unit of weight

The amount of matter in an object

First Term

15

Unit

(1)

Tes

t

4 Fill in the following table:

WeightMassPoint of Comparison

Definition

Unit of measurement

Device of measurement

Direction


5 If an object’s mass = 30 kg on Earth, calculate:a Its mass on the moon.

b Its weight on the Earth.

c Its weight on the moon.

U n i t

U n i t

Un

itUn

it2


Determine some materials that are �good conductors of heat or bad conductors of heat.

Do experiments to show the various �metals to conduct heat.

Determine the usages of the good �and bad conductors of heat.

Compare between the medical �thermometer and Celsius thermometer in usage and structure.

Unit Objectives

Heat is used in our daily life in different aspects. Heat flows from an object to another when they are different in temperature. Some materials are good conductors of heat while others are bad conductors of heat. So, we will see some examples of each type and their different usages as well as different types of thermometers used in measuring temperature.

Unit introduction

Thermal Energy


¹¹picture?


¹¹Share in discu

ssion with ¹¹your classmates and you

r

teacher.

Lesson One

Heat conduction

Lesson Two

Measuring temperature

18


2


Do simple experiments to �determine some materials that are good conductors of heat or bad conductors of heat.

Do experiments to show �the different degrees of various metals to conduct heat.

Determine the usage of the �good and bad conductors of heat.

Objectives

Heat conduction

Heat is one of the most important

energies used in our life. We

use it at home in various areas

such as warming the house,

cooking, water heating and drying

washed clothes.

In industry, heat has countless

usages. It is used in making and

processing food, glass, paper,

textiles, ... etc.

What do you know about heat?

Heat

Temperature

Good conductors of heat

Bad conductors of heat

Basic concepts

19

(2-1

)First Term

We can conclude that:¹¹

The different materials (such as plastic, wood and aluminium) differ ¹y

in conducting heat.

HeatIt is a form of energy that transfers from the higher-

temperature object to the lower temperature object.

TemperatureIt is the degree of hotness or coldness of a body.

Special devices are used to measure temperature. These devices are called thermometers.

Find out the good and bad conductors of heatActivity

What do you need?¹� A glass container, a metal spoon, plastic ruler, wooden pencil, molten wax, hot water, clay, three buttons.

What will you do?¹�

Fix the ruler, spoon and pencil ¹�

to the edge of the container and stick them using clay.Stick buttons on the ruler, ¹�

spoon and pencil using the molten wax.Pour the hot water in the container but not to its edge.¹�

What do you notice?¹� .................................................................................................................................................

What do you conclude? ¹� ..........................................................................................................................................

Fig (2-1) Different materials differ in conducting heat.

What is the difference

between heat and temperature?

UNIT

2

20

Heat conduction

Air is a bad conductor of heat. That’s why it is used in making insulating glass windows.

The window is made by bonding two sheets of glass and maintaining a space between them filled with air to ensure preventing leakage of heat.

Life applications

Materials differences in conducting heatActivity

What do you need? ¹� Frying pan, wooden chopping board, ice cubes

What should you do?¹�

Put the frying pan and the wooden chopping ¹�

board horizontally on the table.Put an ice cube in the frying pan and another ¹�

one on the wooden board.Notice the change of the ice cube in the ¹�

frying pan and the other ice cube on the wooden board. Write down your notes.

What do you notice?¹� .........................................................

What do you conclude? ¹� .......................................................

..................................................................................................................

We can conclude that: ¹¹ materials differ in conducting heat and are classified into two types:

Good conductors of heat:¹y these are the materials that conduct heat and let heat flow through such as copper, aluminium, and iron.

Bad conductors of heat:¹y these are known as insulators that do not let heat flow through such as wood, glass, plastic, paper, liquids and gases especially air.

Fig (2-2) The difference in materials leads to the difference in conducting heat.

Fig (2-3) Double glazed window

First Term

21

(2-1

)

Comparing conducting heatActivity

What do you need? ¹� Two metal racks, three metal rods with the same length and thickness of copper, aluminium and iron, candle, office pins, flame, stop watch.


Lit the candle and put some drops of ¹�

molten wax on the tip of each metal rack.Stick an office pin on each tip of ¹�

each metal stem before the wax gets hard.Put the three metal stem on the two ¹�

metal racks as shown in the figure.Put the tips of the three metal stems ¹�

that do not contain paraffin wax above the flame.Calculate the required time to drop ¹�

the office pins from each rod.Write down your notes in the ¹�

opposite table.

What do you notice?¹� ...................................

.....................................................................................

What do you conclude? ¹� ...........................

.....................................................................................


Different metals differ in conducting heat. ¹y

We find out that copper conducts heat faster than aluminium and iron do.

As a result of heat flow through metals, metals expand and get bigger. So, we find spaces between railways, otherwise they expand and twist; an act which results in train accidents.

Life issues

Time (second)Metal

Aluminium

Copper

iron

UNIT

2

22

Usages of good and bad conductors of heat:

1 Aluminium, copper and stainless steal are used to make cooking pots and kettles in houses and factories.

2 Plastic and wood are used to make handles of cooking pots, kettles and utensils. Moreover, plastic is used to make the iron handle.

3 Heavy blankets and wool clothes are bad conductors. Therefore, it they are used in winter to keep the body warm.

Heat conduction

First Term

23

(2-1

)

1 Complete the following sentences:a All metals are ….......….. conductors of heat.

b ….......….. conducts heat faster than aluminium.

c Some examples of good conductors of heat are ….......….. and ….......…...

d Some usages of good conductors of heat are ….......….., ….......….. and ….......…...

e Some examples of bad conductors of heat are ….......….. and ….......…...

f Some usages of bad conductors of heat are ….......….., ….......….. and ….......…...

2 Put (�) in front of the right statements and (�) in front of the false statements and correct the underlined in the false ones:a All materials are good conductors of heat.

b Copper is a good conductor of heat.

c Cooking pots are made of wood.

d Handles of cooking pots are made of copper.

e Aluminium is a poor conductor of heart.

3 Provide the scientific term for each sentence:a Materials that let heat flow through.

b Materials that do not let heat flow through.

4 Mention the usages of good and bad conductors of heat.

5 Write a paragraph on each of the following concepts:

Exercises

Bad conductors of heatGood conductors of heat

Are classified into

24

UNIT

2


Compare between the �medical and celiesus thermometers.

Appreciate the importance �of thermometers in our daily life.

Objectives

Lesson Two (2 - 2)


Measuring temperature is one

of the important things in our

daily life. It helps us know

the weather temperature which

affects our life skills. We

know our bodies’ temperature

to check our health condition.

Also, it is very important because

some processed food industries

recquire a certain temperature.

But can we find out if an object

is hot or cold by touching it only,

or do we need a device to know

the temperature accurately?

How do you know temperature?

Thermometer

Medical thermometer

Celsius thermometer

Basic concepts

25

First Term

(2-2

)

ThermometerIt is a device used to measure temperature.

How the thermometer worksTo identify how the thermometer works, cooperate

with your classmates in doing the following activity:

Fig (2 - 4): Therometer.

Make a thermometer on your ownActivity

What do you need? ¹� Water, ethyl alcohol, plastic bottle, red color, straw, clay, a glass with hot water, a beaker with iced water.


Fill half the bottle with similar two quantities of water and ¹�

ethyl alcohol.Add some drops of the red color and stir.¹�

Put the straw in the bottle where it does not touch the ¹�

bottom of the bottle.Use the clay to fix the straw and close the mouth of the ¹�

bottle.Cut two cracks in the hard paper then fix the straw through ¹�

the two cracks. Mark the liquid level using a coloring crayon.Put the bottle in a warm place; under a lamp for example; ¹�

and notice what will happen to the liquid inside the straw. Mark the liquid level using a new coloring crayon.

What do you notice?¹� ....................................................................................

What do you conclude? ¹� ............................................................................


The main idea to make a thermometer is changing the volume ¹y

of the liquid according to the temperature. The liquid expands by heating and contracts by cooling.

UNIT

2

26


Types of thermometers

There are many kinds of thermometers:

Medical thermometer¹�

Celsius thermometer¹�

1 Medical thermometer

Structure of the medical thermometer:The medical thermometer consists of:¹�

A transparent glass tube which includes a capillary ¹�

closed from one of its ends.The other end from the capillary tube is connected to ¹�

a bulb filled with mercury.There is a constriction above the bulb which prevents ¹�

mercury from going back to the bulb quickly in order to read the measurement easily.The thermometer scale starts from 35¹� oC to 42oC and every degree is divided into ten parts.

There are some modern digital thermometers which display body temperature digitaly and are used to measure body temperature espicially for children.

Technology applications

Did you know that the temperature of a healthy human is 37oC and it may go up during sickness.


Fig (2 - 5): Medical thermometer

Thick glass tubeConstriction

Glass bulb contains mercury

Capillary tube

Fig (2 - 6):Structure of medical thermometer

First Term

27

(2-2

)

Use the medical thermometer to measure your temperature

What do you need? ¹� A medical thermometer, Ethyl alcohol, paper tissue


Sterilize the medical thermometer using ¹�

ethyl alcohol.Dry the thermometer very well using a ¹�

paper tissue.Shake the thermometer well until ¹�

mercury goes back to the bulb.Put the thermometer under the tongue ¹�

for a minute.Get the thermometer out from the mouth ¹�

and record the reading on it.Sterilize the thermometer using Ethyl ¹�

alcohol and put it in its box.

What do you observe?¹� ......................................................................................................................................................................................................................................................................................................................................................

What do you conclude? ¹� ............................................................................................................................................

........................................................................................................................................................................................................

Activity

Do not seize the thermometer firmly with your teeth in order not to be broken because mercury is toxic.

Be carefulWe can conclude that:¹¹

The medical thermometer is used to measure ¹y

the temperature of the human being.

UNIT

2

28

2 Celsius thermometer

Parts of Celsius thermometer

It consists of:¹�

A transparent glass tube with a capillary tube closed ¹�

from one of its ends.

The other end of the capillary tube is connected to a ¹�

bulb filled with mercury, but there is no constriction above the bulb.

The thermometer scale starts from zero Celsius until ¹�

100 degrees Celsius. Every degree is divided into ten parts.

The Swedish scientist “Andres Celsius” created the Celsius scale in 1747. He considered the zero as the melting point of ice and 100o is the boiling point of water.

He divided the distance into 100 parts, each part is equal to one degree.

Scientists helped humanity

The lower fixed point is the melting point of ice which represents the freezing point

The upper fixed point is the water boiling point

Fig (2 - 8):Celsius thermometer

Fig (2 - 7): The Celsius thermometer measures the water temperature.

Why is mercury preferred in making a thermometer?

1 It is a liquid metal that can be seen easily through the thermometer glass.

2 Mercury is a good conductor of heat.

3 Mercury is a regular expanding material which gives an accurate estimation.

4 Mercury does not stick to the walls of the capillary tube.


First Term

29

Use the Celsius thermometer to measure the liquid temperatureActivity

What do you need? ¹� A Celsius thermometer, a glass of hot tea, a bottle of cold soft drink, a beaker of warm water.


Put the thermometer in the hot tea. Wait ¹�

until mercury rises and stops and record the temperature.Repeat the previous step but with the cold ¹�

soft drink and the warm water and record the temperature of each.

What do you notice?¹� ..........................................................................

What do you conclude? ¹� ..................................................................

TemperatureThe liquid that we need to measure its temperature

Hot tea

Cold soft drink

Warm water


The Celsius thermometer is used in measuring ¹y

the temperature of liquids.Celsius thermometer is known by this name due to the dividing of distance between ice melting point and water boiling point into 100 divisions.

Enrichent information

(2-2

)

While recording the temperature, the thermometer must be vertical. The direction of sight must be perpendicular to the thermometer.

Be careful

UNIT

2

30

The Celsius and the medical thermometers

Compare between:¹�

Celsuis thermometer and medical thermometer: ¹�

Ex

er

ci

se Medical

thermometerCelsius

thermometerPoints of

Comparison

............................................................Structure

............................................................Range of scale

............................................................Constriction

............................................................Used liquid

............................................................Usage


Some thermometers contain two

scales, one represents celsius

scale (oC) and the other represents

fahrenheit scale (oF).

Oc = 32oF and 100oC = 212oF


First Term

31

1 Complete1the following sentences:a The scale of the medical thermometer starts from ….......….. and ends at ….......…...

b There is a constriction in the ….......….. thermometer.

c Form the kinds of thermometers are ….......….. and ….......…...

d The Celsius thermometer is used in ….......….. whereas the medical thermometer is used in….......…...

e The thermometer is ….......…...

2 Put (�) in front of the right statements, and (�) in front of the false statements and correct the underlined in the false ones:a The Celsius thermometer is used for measuring the temperature of the human

being.

b The scale of the medical thermometer starts from zero until 100 Celsius degree.

c The medical thermometer is used for measuring the temperature of liquids.

d There is a constriction above the bulb in the Celsius thermometer.

e The used liquid in the medical thermometer is mercury.

3 Write the scientific term for each of the following statements:a A device used to measure the temperature of the atmosphere.

b A device used to measure the temperature of the human being.

c The liquid used in making thermometers.

4 Compare between the medical and the Celsius thermometer in structure and usage.

5 Write a paragraph on your own on each of the following concepts:

Exercises

The Celsius thermometerThe medical thermometer

Instruments used in measuring the temperature

(2-2

)

Under your teacher’s supervision, write a research on the usages of heat in ¹�our daily life.

Write a research on the usages of good and bad conductors of heat.¹�

Collect some pictures of some of the ¹�modern digital thermometers and write an article about the modern digital thermometers.

Write a research on types of thermometers of ¹�different usages in our daily life in addition to writing the usage of each type.

Use the Celsius thermometer in measuring ¹�the temperature of different drinks used in our daily life.

Research activity

Life applications

Technological applications


32

Design a model of a temperature scale as ¹�mentioned in the lesson and use it to determine the temperatures of different matters.

Have an interview with the school doctor ¹�about:

The proper use of the medical thermometer ¹�

to measure temperature.Dangers of swallowing mercury found ¹�

inside the medical thermometer on human health.

Building models

Healthy aspects

33

UNIT

2

34

Unit (2) Test

1 Complete the following sentences:a We measure temperature by using ….......…...

b ….......….. is used in measuring temperatures of different liquids whereas ….......….. is used in measuring the temperature of the human body.

c ….......….., ….......….. and ….......….. are good conductors of heat

d ….......….., ….......….. and ….......….. are bad conductors of heat

2 Write the scientific term for each of the following statements:

a A device used to measure temperature.

b The materials that allow the flow of heat inside.

c The materials that do not allow the flow of heat inside.

3 Write the most important uses of the good and bad conductors of heat.

4 Fill in the spaces of following tables:

Celsius thermometer

Medical thermometer

Points of comparison

Usage

Structure

Used liquid

scale

Bad conductors of heatGood conductors

of heatPoints of

comparison

Definition

Usage

Examples

Unit (2) Test

First Term

35

Unit

(2) T

est

5 Put a (�) in front of the correct statements and (✘) in front of the false one and correct the underlined in the false ones:

a Medical thermometer is used in measuring the temperatures of different liquids.

b The scale of the Celsius thermometer starts from 35 to 42.

c Aluminum is a bad conductor of heat.

d Wood is a good conductor of heat.

6 Write an explenation for each of the following:a Mercury is used in thermometers.

b The handles of cooking utensils are made of wood or plastics.

c Cooking utensils are made of coper or aluminium.

d There is a constriction in the medical thermometer.

U n i t

U n i t

Un

itUn

it3The Atmosphere


Mention the gases composing the �air and their proportions.

Identify the properties of oxygen. �Determine the importance and uses �of oxygen.

Do experiments illustrating the �properties of carbon dioxide.

Determine the importance and the �uses of carbon dioxide.

Identify the properties of nitrogen. �Determine the importance and uses �of nitrogen.

Unit Objectives

The Earth’s atmosphere consists of a mixture of gasses surrounding it. Nitrogen represents a proportion of 78% of the volume of these gases. Oxygen represents 21% of the volume of this atmosphere. As for the rest of the atmosphere, it consists almost of water vapor, carbon dioxide and other gases such as argon, neon, helium, and others. In the study of this unit, you will identify the properties, uses and importance of the gases that compose most of the air’s components. They are oxygen, carbon dioxide and nitrogen as well as the importance of each one in nature.

Unit introduction


ØØpicture?


ØØShare in discu

ssion with ØØyour classmates and you

r

teacher.

Lesson One

Oxygen

Lesson Two

Carbon dioxide

Lesson Three

Nitrogen

38


3


Mention the gases �composing the air and their proportions.

Identify the properties of �oxygen.

Determine the importance �and uses of oxygen.

Objectives

The atmosphere

Oxygen

Properties of oxygen

Importance of oxygen

Components of the atmosphere

Basic concepts

Oxygen

Green plants are the main

source of oxygen in the air.

Oxygen is produced during the

photosynthesis process in order

to compensate the consumption

of oxygen in the respiration and

combustion processes. So, the

Earth’s vegetation should be

maintained.

What are the sources of oxygen

in the air?

39

(3-1

)First Term

The atmosphere is composed of a mixture of gases surrounding the Earth. They are attracted to the Earth by gravity.

Learn about these gases and their proportions as in figure 2:

You notice that nitrogen represents 78% of the total percentage of these gases. Oxygen represents 21% of the volume of the atmosphere. The remaining part of the atmosphere consists of water vapor, carbon dioxide and other gases such as argon, neon, helium and others.

The atmosphere protects the Earth by absorbing ultraviolet radiation coming from outer space. Also, it adjusts the temperature of the Earth’s surface.

There are large quantities of solid objects in the atmosphere. These solid objects are dust particles, smoke and gases produced by factories, cars, trains and ships. Although solid objects are considered air pollutants, they help in the condensing of water vapor around and falling in the form of drops of rain or snow.

1% Carbon dioxide and other gases

21% Oxygen

78% Nitrogen

Fig (3 - 2): Ratios of gases in the atmosphere

Fig (3 - 1): The atmosphere

What are the components of the

atmosphere?

Fig (3 - 3): Ships send out smoke and gases which pollute the atmosphere.

UNIT

3

40

Oxygen

Oxygen:Oxygen is produced according to the availability

of green plants. It is produced during photosynthesis Figure (3-4). Oxygen exists in the atmosphere in a gaseous state. It consists of two-atom-molecules that have the composition O2 (the first letter of the word oxygen).

Although oxygen is consumed in respiration and combustion, this shortage is always compensated through the sustainability of photosynthesis. Therefore, its proportion stays fixed in the air.

Calculate the percentage of oxygen in the airActivity

What do you need?Ø� A glass basin, a graduated cylinder, a candle, colored water.

What should you do?Ø�

Fix a lighted candle inside a basin containing Ø�

colored water.Cover the candle with the graduated cylinder. Ø�

Determine the water level outside and inside Ø�

the cylinder.

What do you notice?Ø� ......................................................................................................................................................................................................

Share in discussion with your classmates: Which Ø�

component of the air got reduced and replaced with water? ................................................................................................................................................................................................................Calculate the volume of water that rose inside the Ø�

cylinder and record it .......................................................................................................................................................................................

We can conclude that:Ø¹ water rises into the cylinder with one fifth of its volume. This occurrs as a result of air’s loss of one of its components which is oxygen consumed by the candle during burning.

Fig (3 - 4): Plants are the main source of oxygen.

Fig (3-5) Oxygen occupies one fifth of the air volume.

Photovoltaic

Chloroplasts

Oxygen

Water and mineral salts

Carbon dioxide

First Term

41

(3-1

)

We can conclude that:Ø¹

Hydrogen peroxide dissociates in the presence Øy

of manganese dioxide (as a catalyst) into water and oxygen gas (manganese dioxide remains without a change in quantity and properties and so it is called a catalyst).

Oxygen was discovered in China in 800 BC. Then, it was re-discovered by Joseph Priestley in August 1774. Antoine Lavoisier gave it the name “oxygen” in 1778.

Scientists who benefitted humanity

Preparation of oxygen in the laboratoryActivity

What do you need?Ø� A glass flask, a stopper of two holes, a glass funnel with a faucet, a glass tube, a glass container, some glass cylinders, water, hydrogen peroxide (you can get it from pharmacies), manganese dioxide.

Oxygen

WaterHydrogen peroxide

Manganese dioxide

Faucet


Configure the apparatus shown in the figure (3-6) with the assistance of your Ø�

teacher and your colleagues.Pour some manganese dioxide in the flask.Ø�

Fill the funnel with hydrogen peroxide.Ø�

Open the faucet to allow the leaking of some hydrogen peroxide on manganese Ø�

dioxide.What do you notice?Ø� ........................................................................................................................................Close the faucet when the cylinder is filled with gas and then close the cylinder Ø�

mouth and get the cylinder out of the container.Repeat the same steps to examine the properties of oxygen.Ø�

Fig (3-6) Oxygen occupies one fifth of the air volume.

UNIT

3

42

We can conclude that:Ø¹ Oxygen is characterized by its ability to unite directly with most elements forming oxides. If this union is rapid and produces heat and light, it is named “burning”, whereas if it is slow and in the presence of moisture (water), it is named “oxidation”.

Explore the properties of oxygenActivity

What do you need?Ø� Glass cylinders filled with oxygen, water, matches, two litmus papers (red and blue).


Take a cylinder filled with oxygen and test its color Ø�

and smell. What do you observe? .......................................Take a cylinder filled with oxygen and turn it upside Ø�

down in a container filled with water. Does the water rise inside the beaker? .....................................................................Put two wet litmus papers (red and blue) in a cylinder Ø�

filled with oxygen. What do you observe? ...................................................................................................................................................Take a cylinder filled with oxygen, turn it over on the opening of another Ø�

cylinder and insert a burning fragment in the upper cylinder and then in the lower cylinder.

What do you observe?Ø� .............................................................................................................................................

The properties of oxygen can be identified as follows:Oxygen is a colorless, tasteless and odorless gas. figure Ø�(3-8).

It scarcely dissolves in water.Ø�

Oxygen does not burn, but it helps in burning. figure (9-3).Ø�

It has a neutral effect on litmus paper with its two Ø�colors.

Oxygen is heavier than air as it replaces the air.Ø�

The properties of oxygenThere are a lot of compounds containing oxygen such

as hydrogen peroxide (oxygen water) and some salts.

Fig (3 - 7): The two litmus red and bluepapers

Fig (3-9) Oxygen does not burn, but it helps in burning.

Fig (3-8) Oxygen is a colorless gas.

Oxygen

First Term

43

(3-1

)

We can conclude that:Ø¹ the cleansing wire gets burned because the outer surface of the wire is large enough to react with oxygen in the air. So, combustion occurs quickly. The wire becomes heavier after burning because oxygen combines with iron forming iron oxide.

نشــاط

نشــاط

How is the iron rust formed?

Does the weight of materials increases after combination with oxygen?

What do you need? Ø� Some nails or a piece of cleansing dishes wire made of iron, water.


Wet the nails or the cleansing wire with Ø�

water and leave it for several days in a humid atmosphere. What do you observe? .................................................................................................................................................Compare between the iron after and before Ø�

exposure to moisture. This explains the erosion of ironware such as the bridges’ pillars. As time passes, if they are not isolated with paints, they cause damages.

To verify this, do this activity with your colleagues and your teacher.Ø�

What do you need? a scale, cleansing wire, tinfoil Ø�and stove.

What should you do?Ø�Make two balls of cleansing wire of the same Ø�

weight by using the scale.Take one of the balls with a pair of tongs and set Ø�

it on the stove. When the inner part of the ball becomes red, put the ball on an aluminium plate until the flame extinguishes.Using the scale, compare the weight of the two balls again. Which one got Ø�

burned and which did not in terms of weight.Record your observations and discuss them with your colleagues and your teacher.Ø�

Activity

Activity

Fig (3-10) Rusty nails after exposure to moisture

Fig (3-11) A piece of burning cleansing wire.

UNIT

3

44

The importance and uses of oxygen:

Oxygen has a great importance to the human life and all living organisms. Water consists of oxygen united with hydrogen. It is also important for respiration and food combustion processes inside living cells to produce energy necessary for vital processes.

Ozone is also composed of oxygen (O3) which forms the ozone layer. It is a layer in the atmosphere that protects the Earth from harmful radiation that comes from the sun. Oxygen gets compressed in iron cylinders and used in:

Mechanical ventilation for patients who Ø�suffer from breathing difficulties.

During surgeries.Ø�

During diving and climbing mountains. Ø�because oxygen becomes lighter when we have rise above the Earth’s surface.

Oxygen is also used in cutting and Ø�welding metals when combined with acetylene gas to produce “oxy-acetylene” flame whose temperature reaches 3500oC sufficient to melt metals.

Figure (3-12) The ozone layer protects the Earth.

Figure (3-13) Oxygen is used in welding.

Oxygen

First Term

45

(3-1

)

Exercises1 Think and answer: If you know that oxygen does not burn but helps in burning.

What happens to our lives if the oxygen percentage in the air is more than 21%?

2 Explain:

a Oxidation and combustion.

b Components of the atmosphere.

3 Justify:

a Although oxygen is consumed during respiration, its percentage remains stable in the atmosphere.

b Oxygen is created by displacing the water downward in the flask during preparation at the laboratory.

c The atmosphere has a great importance for the continuity of life on the planet.

4 Oxygen has a great importance for life on the planet. Water consists of oxygen united with hydrogen. Give other examples of the importance of oxygen and its uses.

5 Write a paragraph of your own about each concept of the following components of the atmosphere:

Oxygen 21%

Nitrogen 78%

Carbon dioxide and

other gases 1%

Components of the atmosphere

46

UNIT

3


Identify sources of carbon �dioxide emission.

Do experiments �illustrating the properties of carbon dioxide.

Determine the importance �and the uses of carbon dioxide.

Objectives

Carbon dioxide

Basic concepts

Lesson Two (3 - 2)

Carbon Dioxide

The presence of carbon dioxide

in the atmosphere produces

benefits for all living organisms.

It is one of the bases of

the photosynthesis process

that green plants make. During

this process, plants make the

nutrients for living organisms.

On the other hand, the increase

of the percentage of carbon

dioxide in the air leads to the

suffocation of living organisms

as well as global warming.

What are the benefits

and harms of carbon

dioxide?

47

First Term

(3-2

)

Carbon dioxide is a chemical compound found in the form of a gas in its natural state in the atmosphere by a slight percentage 0.03%.

Its molecule consists of one carbon atom linked with two oxygen atoms. It has the symbol of CO2 (figure 3-14).

Despite the fact that carbon dioxide is very important in the photosynthesis process of plants in order to build their bodies and compose food for all other living organisms, the increase of its percentage causes severe harms to the Earth’s climate and raises its temperature.

Therefore, the removal of forests leads to the increase in carbon dioxide percentage in the air.

Carbon dioxide resources:Carbon dioxide is emitted as a result of the

combustion of organic materials such as:

WoodØ�

CoalØ�

OilØ�

GasolineØ�

Tobacco (The material cigarettes are made of).Ø�

In recent years, it has been observed that the percentage of this gas in the atmosphere is rising. This is due to the burning of massive amounts of fuel in industrial plants and means of transportation engines.

Oxygen atom

Carbon atom

Oxygen atom

Fig (3-14) A model of a carbon dioxide molecule

Fig (3-16) Carbon dioxide is emitted from industrial plants

Fig (3-15) Plants absorb carbon dioxide

UNIT

3

48

Carbon Dioxide

Detect carbon dioxide in the exhaled air

Detect carbon dioxide during the plants’ respiration

What do you need?Ø� A jar or test tubes, clear limewater, a long juice straw)


Pour some of limewater in the Ø�

jar.Blow in limewater for two Ø�

minutes using the juice straw.

What do you observe? Ø� ........................

...................................................................................

...................................................................................

.........................................................................

What do you need?Ø� Germinated bean or pea seeds, a jar or test tubes, clear limewater, a plastic tube, clay).


Put some germinated bean seeds in a jar. Ø�

Make a hole in the jar cover and insert a plastic tube Ø�

through it. Fix it carefully using the clay as shown in figure (3 - 18). Insert the other end of the tube in a jar of clear Ø�

limewater and leave it for a while. Observe the change in the limewater.

What do you observe?Ø� .......................................................................................................................................................................................................................

Activity

Activity

How is carbon dioxide produced?

Carbon dioxide results from respiration of living organisms and combustion of organic substances. How can we detect the carbon dioxide inside these substances?

Fig (3-18) Seeds are produced during the respiration of germinated carbon dioxide.

Fig (3-17) Exhalation air contains CO2

First Term

49

(3-2

)

Detect carbon dioxide during a candle burning

What do you need? Ø� A cylinder, a candle, clear limewater.


Introduce a lighted candle into a cylinder by using a combustion spoon.Ø�

Cover the candle with a glass cover and observe it until the candle Ø�

extinguishes.Remove the cover and pour a little of clear limewater inside the cylinder.Ø�

What do you observe?Ø� ..............................................................................................................................................................................................................................................................................................................................................................

Activity

Turbid limewater. A candle burning produces carbon dioxide CO2.

From the previon activities, we can canclude that:Ø¹

Carbon dioxide is produced from the respiration of humans (the Øy

exhaled air). It is also produced from the combustion of organic substances. It turbids the clear limewater.

Fig (3-19) What is the effect of CO2 on limewater?

UNIT

3

50

Preparing carbon dioxide gas and discovering its propeties

What do you need?Ø� Glass cylinders, glass flask with a stopper of two holes, a long funnel, diluted hydrochloric acid, calcium carbonate, a shaped U-shaped glass tube.


Canfigure the apparatus. Ø�

shown in Figure (3 - 20).Pour a little acid on the Ø�

calcium carbonate.Collect a set of cylinders Ø�

filled with carbon dioxide by displacing the air upward.

Activity

CO2

Fig (3-21) the candle extinguishes in CO2.

Fig (3-22) The magnesium ribbon keeps burning in carbon dioxide.

Fig (3-20) Preparation of Carbon dioxide

carbon dioxide gas

calcuim carbonate

dilute hydrochloric acid

Tap

cylinder

Carbon Dioxide

Use the cylinders (filled with carbon dioxide) to Ø�do the following experiments so as to identify its properties

1 Through the activity of preparing carbon dioxide, you may have observed that it is collected by displacing the air upwards (Figure 3-20) What can you conclude? ..........................................................................................................................

2 Turn a cylinder filled with CO2 upside down on a lighted candle. Record your observations and explain them (Figure 3-21) ..............................................................................

3 Insert a lighted magnesium ribbon in a cylinder filled with CO2 using a combustion spoon (Figure 3-22) What do you observe? ...................................................................

4 Squeeze half a lemon on a little of sodium bicarbonate in a glass or open a soft drink bottle. Observe the color of the evolving carbon dioxide and identify its smell. Record your observations and explain them ...............................................................................................................................................

First Term

51

Through the previous activities, we can determine Ø¹

the properties of carbon dioxide:

It is colorless and odorless.Øy

It is heavier than the air and so it is collected by Øydisplacing the air upward and replacing it.

It easily dissolves in water, so it is not collected by Øydisplacing water as in preparing oxygen.

It does not burn and does not help in combustion. ØySo, it is used for extinguishing fires.

The magnesium ribbon keeps burning and turns Øyinto a magnesium oxide (with white color) and the carbon (coal) deposits on the wall of the cylinder.

Importance and uses of carbon dioxide: it is used in:

Refrigeration on converting it into a liquid by Ø�pressure and cooling. Then, pressure is relieved composing dry ice that we use in refrigeration.

It is used in extinguishing fires because it does Ø�not burn and does not help in burning.

It is used to make soft drinks.Ø�

It is used to make bread bubbled as yeast which Ø�produces carbon dioxide by fermentation when it is added. Carbon dioxide gets expanded due to the heat making bread porous and tasty.

Carbon dioxide contributes in the photosynthesis Ø�process in green plants leading to the production of food as well as the production of oxygen.

Fig (3-23) Carbon dioxide used in extinguishing fires

(3-2

)

Man gets suffocated if he breathes carbon dioxide. It is called the silent killer because we can not see it, taste it or even smell it. Breathing in a closed space with no or bad ventilation leads to a gradual decrease in oxygen and an increase in carbon dioxide. Quickly, everyone gets suffocated and loses consciousness and then dies.


UNIT

3

52

Exercises1 Suggest some experiments which prove that carbon dioxide is:

a Is heavier than air.

b Dissolves in water.

c It does not burn and does not help in burning.

2 What happens to our lives on earth if:

a The percentage of carbon dioxide in the air increases.

b The percentage of carbon dioxide in the air decreases.

3 Justify:

a Clear limewater is used to detect the presence carbon dioxide.

b Carbon dioxide is used in extinguishing fires.

c Carbon dioxide has a great importance for the continuity of life on Earth.

4 Prove by an experiment that carbon dioxide is produced during the burning of a candle. What are the materials and tools used?

Carbon Dioxide

First Term

53

(3-2

)

5 Give reasons for the following statements:

a Carbon dioxide is used to extinguish fires.

b Yeast is added to the dough on making bread.

c Clear limewater gets turbid if carbon dioxide passes across it.

d The environment suffers from the increase of carbon dioxide perceutage.

6 Write a paragraph about each of the following concepts.

Resources of carbon dioxide

Properties of carbon dioxide

Importance and uses of carbon

dioxide

Carbon dioxide gas

54

UNIT

3


Identify the properties of �nitrogen.

Identify the importance of �nitrogen.

Objectives

Nitrogen

Properties of nitrogen

The importance of nitrogen

Basic concepts

Lesson Three (3 - 3)

Nitrogen

Nitrogen :It is a chemical element found

in nature in the form of a gas

and referred to by the symbol

N2 as the nitrogen molecule

consists of two atoms of

nitrogen.

Nitrogen is also called azote

which means (lifeless) because

it does not help in burning and

is not included in the process

of respiration. It is a colorless, tasteless and odorless gas and hardly dissolves in water. It is a main component in all proteins. Daniel Rutherford,

discoverer of nitrogen

What do you know about nitrogen?

55

First Term

(3-3

)

The existence of nitrogen Nitrogen represents 78% of the Earth’s atmosphere

and contributes in the composition of all living tissues in all living organisms. They need nitrogen to live as nitrogen composes the most important part in protein.

Nitrogen oxiden are formed in the atomsphere during lightening (fig. 3-24) which reaches soil with rain water. Legumes such as clover, peas and soybeans produce proteins from atmospheric nitrogen by the help of a specific type of bacteria that live in their roots.

Preparation of nitrogen in the laboratory

What do you need?Ø� Sodium or potassium, hydroxide glass flask, a hot copper, glass basin, a glass cylinder, water connecting tubes.


Make an apparatus used for the preparation of nitrogen as in figure (3-25).Ø�

Open the water tap to push the air inside the first flask. Air passes through the Ø�

solution of sodium or potassium hydroxide to absorb small amounts of carbon dioxide from the air.Let the air pass over the hot copper to combine with oxygen formed in the air.Ø�

Collect the produced gas (nitrogen) through the displacement of water Ø�

downward.Record your observations about its solubility in water Ø� .................................................................

........................................................................................................................................................................................................

Fill some cylinders to do activities so as to identify the properties of nitrogen.Ø�

Activity

Fig (3-24) Oxygen reacts with nitrogen in the event of lightning composing compounds known as nitrogen dioxides.

Fig (3-25) preparation of nitrogen from air

mixed air

water from the tap

heated copper reacts with oxygen

heat

nitrogen

water

concentrated sodium or potassium hydroxide

UNIT

3

56

Nitrogen

Properties of nitrogen:Do the following activities to identify properties of Ø�nitrogen:

1 Notice the color, taste and smell of nitrogen in one of the cylinders that you filled with nitrogen while preparing it. (Figure 3-25). Record your observations: ....................................

2 You have may noticed during nitrogen preparation that it is collected by the displacement of water downward . Also, it does not react with hot copper as what happened with oxygen. Discuss this with your colleagues. Explain: .....................................................................................................................................

3 Place a match close to the gas rising from the cylinder and record you observations: .........................................................................

4 Notice your teacher while lighting a ribbon of magnesium and putting it in the cylinder filled with nitrogen. Record your observations: .......................................................................................

5 Notice the smell of gas rising as a result of the magnesium burning in nitrogen. Then, put a wet red litmus paper close to the rising gas. Record your observations: .....................................................................................................................................................................

You can fix a nail in a piece of wood by a banana. If quickly immersed in liquified nitrogen, it will freeze quickly and become solid. Therefore, liquified nitrogen is used in the rapid cooling of food, medicines and vaccines which are spoiled by heat.

Amusing information

Liquified nitrogen is used for cooling

Fig (3 -26) the burning of magnesium in nitrogen

We can identify the most important properties of nitrogen as follows:

Nitrogen is a colorless, tasteless and odorless Ø�gas.

It scarcely dissolves in water. Ø�

It does not help in burning. Ø�

When it combines with a lighted magnesium Ø�ribbon composing a white substance. By adding a little water, a very pungent smell “ammonia” emits. (figure 3-26).

Nitrogen can be condensed to a liquified Ø�state.

First Term

57

(3-3

)

The importance and uses of nitrogen:

Nitrogen is recently used in filling car tires Ø�for the relative constancy of its volume at the change of temperature.

Liquid nitrogen is used as a treatment to Ø�skin tumors.

It contributes in composing gunpowder Ø�and ammonium nitrates included in the composition of soil fertilizers.

Liquid nitrogen is used for cooling food Ø�products with the aim of preservation or transferring purposes.

It is commercially used in the manufacture Ø�of ammonia to produce fertilizers (figure 3-28).

Nitrogen is used as an inactive material in Ø�the tanks of liquified explosives and during the manufacture of electronic devices.

Nitrogen is used to make stainless steel.Ø�

Small amounts of nitrogen are used to fill Ø�some types of lamps.

It is used to store petroleum and some Ø�flammable materials.

Fig (3-27) Nitrogen is used in filling tires.

Fig (3-28) Fertilizers

UNIT

3

58

Exercises1 Write (�) in front of the correct statements and (�) in front of the false ones

and correct the underlined if incorrect:

a Nitrogen reacts easily with other elements. ( )

b Legumes such as clover and peas benefit from the nitrogen in the air. ( )

c Nitrogen is also called azote which means life less gas. ( )

d Nitrogen is used as an inactive material in the tanks of liquefied

explosives and flammable materials. ( )

2 Justify:

a Nitrogen is recently used in filling car tires.

b Liquified nitrogen is used for cooling food products and medicines.

c The main source of nitrogen is the air.

d We prepare nitrogen by passing air across the sodium hydroxide or potassium.

e Nitrogen contributes in the composition of all living tissues.

3 Explain how you get:

a Nitrogen from the air.

b Oxygen from oxygen water.

c Carbon dioxide from wood.

d Ammonia from nitrogen.

Nitrogen

First Term

59

4 Write a paragraph about each of the following concepts.

Resources of nitrogen

Properties of nitrogen

Importance and uses of

nitrogen

Nitrogen gas

5 Mention how you can get nitrogen.

6 Mention the properties of nitrogen.

7 Mention the importance and uses of nitrogen.

(3-3

)

How do you prepare clear limewater to detect Ø�carbon dioxide? Dissolve suitable amount of calcium hydroxide in a glass of water and then pour it in a clean beaker and save it until it is used.

What do you know about harms caused Ø�by soft drinks?

Carbon dioxide is a key component Ø�

in the manufacture of soda water. Drinking too much of it is unhealthy. Scientists call it the useless food because it does not contain any nutrients except sugar.When you have soft drinks, you Ø�

swallow amounts of carbon dioxide.

Life applications

Lab activity


60

Make a model of a device for Ø�electrical analysis of water to oxygen and hydrogen.

Water is a simple chemical Ø�

substance made up of oxygen and hydrogen. Each water molecule has two hydrogen atoms and one oxygen atom.When the electric current passes Ø�

in the water it changes to oxygen and hydrogen.This process is called electrolysis. Ø�

In the absence of electrolysis device (Huffman voltmeter), we use that simple model.

Tools:Ø�

A 9-volt battery, two pencils - a bit of salt (to make the water a good Ø�

conductor of electricity) paperboard - conductor wires - a small cup of water.

Warning:Ø�

Do not use regular electricity in water because it is dangerous to Ø�

your life.

Making models

61

UNIT

3

62

Unit (3) Test

Unit (3) Test1 Put (�) front of the correct statements and (�) in front of the false ones and

correct the underlined word:

a The nodular bacteria fix air oxygen in roots of leguminous plants

such as beans and clover. ( )

b Characteristics of nitrogen are that it is a colorless, odorless and

tasteless and easily dissolves in water. ( )

2 Justify;

a Nitrogen is used in filling cars tires.

b Nitrogen is used to store petroleum and some flammable materials.

c The main source of nitrogen preparation is the air.

3 Explain the following statements:

a Nitrogen contributes in the composition of all living tissues.

b Forest cutting and fires lead to the increase of carbon dioxide percentage in nature.

c Carbon dioxide is used to extinguish fires.

First Term

63

Unit

(3) T

est

4 Notice the following figure and write down the labels on the figure:

U n i t

U n i t

Un

itUn

it4


Identify the structure and functions �of the human nervous system.

Explain the occurrence of reflex �action.

Identify the importance of the �human nervous system and ways of maintaining it.

Identify the structure of the human �muscular system.

Explain the importance of muscles �and joints for movement.

Identify some ways to maintain the �locomotory system.

Unit Objectives

This unit deals with the structure and function of nervous and locomotory systems in your body. It also deals with the ways of maintainance of both systems and their importance for your health.

Unit introduction

Structure andFunction


¹¹picture?


¹¹Share in discu

ssion with ¹¹your classmates and you

r

teacher.

Lesson One

Human Nervous System

Lesson Two

Human Locomtory System

66


4

Human nervous system


Identify the structure and �functions of the human nervous system.

Explain the occurrence of �reflex action.

Identify the importance of �the human nervous system and ways of maintaining it.

Objectives

Brain

Spinal cord

Reflex action

Basic concepts

Your nervous system is a communication and controlling device. It consists of the brain, the spinal cord and nerves. This important system receives information from your environment and from your body. Then, it interprets this information and makes the body respond to it.

Your nervous system lets you know if things are hot, cold, sweet, bitter, rough or smooth. It adjusts your movements, protects you from harm, makes you feel pain, makes you solve problems and learn music.

In addition, the nervous system adjusts the responses that require emotions. It makes you happy, sad, angry or calm. You will not be mistaken if you think that the nervous system is of the most importance to your body. It oversees the multiple functions performed by the human body such as moving, feeding, digestion, breathing, thinking and others. Then, it coordinates and requlates them.

Brain

Spinal cord

nervous

Read the lesson introduction

and notice the new concepts.

Record and discuss them with

your colleagues.

67

(4-1

)First Term

Structure and functions of the human nervous system:

The nervous system consists of two major systems:

The central nervous system.¹�

The peripheral nervous system.¹�

What are the components of Neuron?

What do you need?¹�

A microscope, a slide of a neuron


Examine a slide of a neuron by a ¹�

microscope.What do you observe? ¹� .................................................

.......................................................................................................The neuron consists of two main parts:¹�

The cell body – the axon¹y

Activity

Neuron is the building unit of the

nervous system

Fig (4 - 1): The neuron

1 Cell body: It contains a nucleus, cytoplasm and a plasma membrane. ¹�

There are some branches extending from the neuron`s body called dendrites ¹�

connected to neighboring neurons composing the synapse.

2 The axon:It is a cylindrical axis ¹�

covered with a fatty layer called myelin sheath. The axon ends with nerve endings (Axon terminals) connected to muscles or form a synapse with other neurons (See Figure 4 – 2).

cell body

nucleus

dendrites

axon

terminals

Fig (4 - 2): The structure of a neuron

UNIT

4

68


Examine the sheep’s brainActivity

What do you need? ¹�

Fresh sheep’s brain - dissecting tools (forceps - dissecting needle - scalpel).

What should you do?¹�Examine the sheep’s brain and identify ¹�

its main parts.Make a longitudinal cutting through ¹�

the hemispheres using the scalpel.Notice the difference in the color ¹�

inside and outside the brain.

Record your observations: ¹� ..........................................................................................................................................

........................................................................................................................................................................................................

First: The central nervous system The system is composed of:

The brain¹�

The spinal cord¹�

1 The brain:It is the main control center in your body. It directs

and coordinates all the processes, ideas, behaviors and emotions. It is like the computer.

The brain is located inside a bony box called the skull that works to protect it. It is a nerve block containing millions of nerve cells. It is more complicated than the computer.

Observe Fig (4-3) which illustrates the structure of the ¹�brain. It consists of:

1 Cerebrum

2 Cerebellum

3 Medulla ablongata

Fig (4 – 4): A sheep’s brain

Cerebral hemispheres

medulla ablongata

cerebellum

Fig (4 – 3): Structure of the brain

First Term

69

(4-1

)

1 Cerebrum:

It is the largest part of the brain. It is divided into a right and a left halves which are called the cerebral hemispheres. The outer surface of the hemispheres is called cerebral cortex and it is gray. The hemispheres are characterized by having many convolutions and folds on their surface.

The most important functions of the hemispheres ¹�are:

Controlling the voluntary movements of the body ¹�

such as running in races.Receiving nerve impulses from sense organs (eyes, ¹�

ears, nose, tongue and skin) and send appropriate responses to these impulses.Contain the centers of thinking and memory.¹�

2 Cerebellum:

Cerebellum lies at the back area of the brain below two hemispheres.

Its most important functions are:¹�

Maintaining the balance of the body during ¹�

movement.

3 The medulla oblongata:

The medulla oblongata is located in front of the cerebellum. It connects the brain with the spinal cord. Its function is regulating the involuntary processes of the body as:

Regulating heart beats.¹�

Regulating the movement of the respiratory system ¹�parts during breathing.

Regulating the movements and functions of the ¹�digestive system.

2 Spinal cord:The spinal cord extends in a channel within a

series of vertebrae in the backbone. It is cylindrical and the spinal nerves extend from it.

¹The adult human brain weighs about 1.5 kg. Some people believe that if the human brain gets bigger the intelligence will increase. But this is not true, all adults have an equal brain sizes.

Do you know? ؟

The spinal cord

Spinal nerve

Vertebrae of the backbone

Cerebral hemispheres

Fig (4 – 5): the brain’s hemispheres.

Fig (4 – 6): Structure of the spinal cord

UNIT

4

70

Examine a cross-section of the spinal cordActivity

What do you need:¹� A microscope - ready made slide of the spinal cord.


Examining the slide of the spinal cord by ¹�

a microscope.Record your observations: ¹� .....................................

...........................................................................................................

...........................................................................................................

.........................................................................................................

On examining a slide of the spinal cord, ¹�

it is clear that the spinal cord consists of an internal substance that is the grey matter and it appears in the shape of letter H surrounded by the white matter.

Functions of the spinal cord:1 It delivers nerve messages from body

organs to brain and vice versa.2 It is responsible for the reflexes such as

the withdrawal of the hand quickly on touching a hot surface.

Second: The peripheral nervous systemIt is the nerves which emerge from the

central nervous system; i.e. the brain and the spinal cord. The function of these nerves is to get sensory information and kinetic responses between the central nervous system and all parts of the body. There are 12 pairs of nerves which emerge from the brain known as cranial nerves and 31 pairs of nerves emerge from the spinal cord known as spinal nerves.

Fig (4 – 7):Structure or spinal cord

White matter

Gray matter

Brain

Spinal cord

Nerves


Fig (4 –8):The peripheral nervous system

First Term

71

(4-1

)

Reflex actionWhen the body is subjected to an external stimuli such

as light, heat, and smell, it makes an involuntary response by The nervous system. It is called the reflex action. Why does the withdrawal of a hand occur quickly upon touching plants’ thorns or a hot surface?

نشــاطExplanation of the reflex action

In this activity, trace the stages of the reflex action:¹�

The girl touched a plant with sharp thorns. She quickly picked up her hand. How ¹�

did this occur?The severity of the thorns affects the nerve endings in the fingers resulting in ¹�

nerve impulses.Nerve impulses are transmitted to the spinal cord through a sensory nerve fiber.¹�

Nerve impulses are transmitted from the spinal cord through a motor nerve fiber ¹�

to arm muscles (without the brain’s intervention). Muscles contract and the arm withdraws away from the thorns.Other nerve impulses are transmitted from the spinal cord to the sensory centers ¹�

in the brain which leads to the true sense of pain.

What do you conclude? ¹� ……………………………………………………………..……………….........................

Explain: ¹� What happens when you suddenly touch a hot object?

Activity

Fig (4 –9):The reflex action

spinal cord

Sensory nerve fiber

motor nerve fiber

A muscle

Sensory nerve endings under the skin

Thorns of the plant

Sensory nerve fiber

1

2

4

5

3

UNIT

4

72

The importance of the human nervous system and ways of maintaining it.

Now, it is clear that the nervous system has a special importance because its main function is to carry nerve messages from one of the areas of the body to another area. It works on regulating and coordinating all the vital processes within the body. It also receives the external stimuli that surround the human being through the sensory organs and identifies and interprets them.

Examples of reflex actionWithdrawing the hand quickly when it touches a hot surface.¹�

Blinking when something gets close to the eye.¹�

What are the other examples of the reflex actions that you know? ¹� ....................................

..........................................................................................................................................................................................................

.......................................................................................................................................................................................................

The hand touches a hot thing A thing gets close to the eye


First Term

73

(4-1

)

Ways of maintaining the human nervous system:

Reducing the intake of the stimulating ¹�substances such as coffee and others as they affect sleeping periods and heart beats and lead to nervous tension as well.

Stay away from tranquilizers and ¹�stimulants.

Not exhausting the sensory organs ¹�by sitting for long periods in front of the computer and television.

Giving the body a sufficient period ¹�of rest especially during sleep.

Avoiding extreme exciting ¹�situations.

Staying away from sources of ¹�pollution because they passively affect the nervous system as noisy places and smoke emitted from exhausts of cars, factories, ...etc.

Doing physical exercises.¹�

Reducing the intake of coffee

Avoiding sitting for long periods in front of computer

Staying away from sources of pollution.

UNIT

4

74

1 Choose the correct answer:a The number of cranial nerves is …………………. pairs of nerves.

1 31 2 21 3 12

b The grey matter in the spinal cord appears in the shape of letter …………………..

1 H 2 F 3 A

c The cerebellum is responsible for …………………..

1 thinking 2 the body’s balance 3 the reflex

d One of the components of nerve cell is the presence of …………………..

1 Blood vessels 2 cover of myelin 3 dendrites

e …………………. controls reflex actions

1 Spinal cord 2 Cerebellum 3 cerebrum

2 Write the scientific term for each of the following statements:a Automatic response of the body to different stimuli.

b Part of the nervous system responsible for reflex actions.

c The basic structure unit of the nervous system.

d Linked to the brain through the spinal cord and is responsible for involuntary actions.

e Consists of a grey matter in the form of H letter surrounded by the white matter.

3 Locate the following parts in the human body:a Cerebellum

b Spinal cord

c Hemispheres

d Medulla oblangata


Exercises

First Term

75

(4-1

)

4 Mention the importance of:a Medulla oblongata.

b Spinal cord.

c Skull.

d Cerebellum.

e The two hemispheres.

5 What happens when:a Sitting for long times in front of the computer.

b Your finger gets pricked by plant thorns.

c Continuous exposure to contaminated air from factories’ smoke.

d Approaching something to the eye.

6 Give reasons for each of the following:a Damage of the medulla oblangata causes death.

b The brain is located inside the skull and the spinal cord extends through the inside of the backbone.

c It is important not to take sleeping pills without the doctor’s prescription.

d Withdrawal of the hand quickly when it suddenly touches a hot surface.

76

UNIT

4

Objectives

Skeleton

Joints

Muscles

Basic concepts


Identify the components of �human locomotory system.

Explain the importance of �the muscles and joints to movement.

Identify some ways to �maintain the locomotory system.

Lesson Two (4 - 2)

Human Locomotory System

Movement is the ability of the

organism to change its position

from a place to another. It is

one of the characteristics that

distinguish living organisms from

non-living things.

Movement is one of the most

prominent life aspects in the human

life. It helps man to move from

one place to another seeking benefit

or away from harm. Movement

occurs with participation and

integration of special organs and systems such as the skeletal, muscular, and nervous systems that regulate and coordinate the required movement.

Read the lesson introduction

and notice the new concepts.

Record and discuss them with

your colleagues.

77

First Term

(4-2

)

The structure of human locomotory system:Through the work of muscles and bones together,

your body can move. Locomotory system consists of two major systems:

The skeletal system¹�

The muscular system.¹�

The skeletal systemThe human skeletal system ¹�consists of:

The axial skeleton¹�

The appendicular ¹�

skeleton

The axial skeleton

The axial skeleton consists ¹�of the following parts:

The skull¹�

Backbone ¹�

Rib cage ¹�

Notice the parts in figure ¹�(4 - 10).

The skull: ¹� is a bony box that contains cavities for the eyes, ears and nose. Its function is to protect the brain.Backbone:¹� consists of 33 vertebrae with cartilages between them to prevent their friction during movement. The backbone function is to allow the body to bend in different directions and protect the spinal cord inside.The rib cage:¹� consists of 12 pairs of ribs. The first ten pairs are connected anteriorly to the sternum (breastbone). The function of the rib cage is to protect the lungs and the heart, in addition to helping in the inhalation and exhalation processes.

skull

femur

pelvis

Fore arm bones

hand bones

radiusvertebral column

scapula

ulna

foot bones

shaft bones

Ribs

knee joint

humerus

Fig (4 –10): The human skeleton.

What are the components of human

locomotory system?

UNIT

4

78


Appendicular skeleton:It consists of the bones of upper and lower limbs.¹�

1 Bones of the upper limbs: are connected to the shoulder bones

humerus bone, forearm bones and hand bones. ¹�

The function of the two upper limbs is to allow ¹�

eating, drinking, writing and holding things.

2 Bones of the lower limbs:

Femur, shaft bones and foot bones.¹�

The function of the lower limbs is to allow ¹�

walking, running, standing, sitting and carrying the rest of the body.

Joints and their significance to movement:Can a human move if all of his bones are fused together? ¹�(yes/no).

Identify the locations where bones meet in the body by ¹�joints. All the joints of the body allow the movement between the bones.

Joints are three types:¹�

1 Immovable joints: such as the joints between the bones of the skull. They do not allow any movement.

2 Slightly movable joints: they allow movement in one direction only such as the knee and elbow joints.

3 Freely movable joints: they allow movement in all directions such as the shoulder, wrist and thigh joints.

humerus

Shoulder bones

fore arm

hand bones

patella

bursaFemur

ligamentstibia

fibula

cartilage

Fig (4 –12): Bones of lower limbs.

Fig (4 –13): Slightly movable joint

femur

shaft

bones

Fig (4 –11): Bones of upper limbs.

Pelvic bones

First Term

79

(4-2

)

What type of movement do joints perform? Activity

Notice the movement of ¹�the body of this player and determine:

The types of different joints ¹�

.....................................................................

.....................................................................

................................................................

How to perform the ¹�

movement especially in the places referred to by arrows ....................................................................

....................................................................

....................................................................

.......................................................

The role of the muscles in performing movementOur muscular system is considered the engine of

our body. Muscles generate mechanical energy and movement to the body. Movement is generated by the ability of muscular cells to contract and relax.

Muscles are fixed to bones by long strips called tendons.

You may be able to move your muscles willingly such as the limbs trunk, face and abdominal wall muscles. They are called the voluntary muscles.

There are other types of muscles that work automatically and you can not control or even be aware of their movements such as The gastrointestinal tract, The blood vessels and The bladder muscles. They are called involuntary muscles.

Fig (4 –14):A basket ball player

¹The human body contains 650 muscles. The biggest muscle size is at the bottom of the body while the smallest is in the ear.¹Humans use 200 muscles during walking.

Do you know? ؟

A B

C

D

UNIT

4

80

A healthy food rich in calcuiem

Do not carry heaving objects

The role of muscles in the movement of the handwrist


Notice the two figures (a - b) which muscles ¹�

contract and which relax in both cases? ....................

.......................................................................................................................Which muscles move in contracting and relaxing? ¹�

............................................................................................................................

........................................................................................................................What is the function of the joint in bending and ¹�

extending the arm? .................................................................................................................................................................................................How are the muscles linked to bones? ¹� .........................

...........................................................................................................................

............................................................................................................

Activity

How can you maintain your locomotory system?Commitment on vaccinating children according to ¹�Ministry of Health’s instructions as well as giving children polio vaccinations at accurate times.

Eating healthy food rich in calcium, phosphorus ¹�and vitamin D to prevent bone diseases such as steomalacia and rickets.

Avoiding any behavior that leads to fractures and ¹�sprains such as jumping from high places and making violent movements.

Avoid carrying heavy things that exceed your ability ¹�to protect the skeleton, especially your backbone.

Sitting and standing correctly during studying or ¹�reading to avoid straining the neck or backbone vertebrae.

Exposing the body to sunlight for suitable periods ¹�due to its importance in providing the body with vitamin D.

Exercising regularly.¹�

Front muscle

Back muscle

Front muscle

Back muscle

Fig (4 –15): The arm in many positions.


a

b

First Term

81

(4-2

)

1 Write the scientific term for each of the following statements:a Structure which consists of the skull, backbone and rib cage.

b Axis of the skeleton in the human body.

c What fixes muscles to bones.

d The type of skeleton which includes the bones of upper and the lower limbs.

e Two bones meeting area.

2 Determine the type of the following joints:a The knee joint

b Elbow joint

c Shoulder joint

3 The following figure shows the arm in two different cases:a Write the names of the bones and the muscles on the figure in

the two different cases.

b Describe what happens to the muscles during each case .

4 What happens if:a Hip joint has a limited movement.

b The front arm muscle relaxes and the back arm muscle contracts.

5 How can you maintain your locomotory system?

6 Rewrite the following statements after correcting the under-lined words:a The skeleton of lower limb consists of humerus bone, 2 fore arm bones and bones

of the hand.

b Knee joint is a freely movable joint.

c Shoulder joint is an immovable joint.

d Joints link bones with muscles.

e Tendons are the sites of bones meeting.

1

2

Exercises

Use simple environmental materials (coloring ¹�pencils - clay - a wooden board - paper cardboard ...) to make a model of the nervous system. Present it in the science laboratory or school gallery.

You studied the importance of maintaining ¹�the nervous system and you know that the drug spreading among young people and individuals is a dangerous phenomenon that leads to the destruction of the health of the addictive person, especially the nervous system. Discuss this topic in an article on the school radio pointing out the risks reflected on the individual and society as a result of addiction and its negative effects on public health and the health of the nervous system.

Life issues

Making models


82

You learned that the human ¹�movement is coordinated by two basic systems: the skeletal system and the muscular system. These two systems need to be maintained. Discuss the importance of this in a two-page research supported by pictures using the school library and the internet. Attach your work to your portfolio.

The human body requires practicing ¹�sports activities to maintain the locomotory system. Visit a gym to identify different mechanisms that can be trained in order to strengthen the skeletal system and muscles.

Healthy issue

Research activity

83

UNIT

4

84

Unit (4) Test Choose the correct answer:

Myelin sheath surrounds the .................

1 nerve cell axon.

2 cerebellum.

3 spinal cord.

Reflex action takes place through the .................

1 medulla oblongata.

2 cerebral hemispheres.

3 spinal cord.

The joint in the location of meeting of .................

1 two bones.

2 a muscle with a bone.

3 two muscles.

................ are what fix muscles in bones.

1 Tendons.

2 Joints.

3 Muscle fibres.

Skulls joints are .................

1 immovable.

2 slightly movable.

3 free movable.

Give the scientific term for each of the following statements: The building unit of nervous system.

What fixes muscles in bones.

The organ which consists of an internal H-shaped grey matter surrounded with a white matter.

The autonomic body response towards different stimuli.

The skeleton which includes the upper and lower limbs.

Unit (4) Test

First Term

85

Unit

(4) T

est

Mention the location of the following parts in human body: Medulla oblongata.

The H-shaped grey matter.

The cerebellum.

The spinal cord.

State the importance of each of the following: Tendons.

Cerebellum.

Joints.

Cerebral hemispheres.

Rib cage.

Give reasons: The rapid withdrawal of the hand on sudden touching thorns of a plant.

Muscles play an important role in human movement.

Damage of medulla oblongata may lead to death.

86

General questions on science – first term

General questions on science – first term

First: objective questions:- Choose the correct answer:

The mass of a body on the moon surface is 10 kgm so its mass on earth surface equals:

10 kgm. 10 Newton.

60 kgm. 60 Newton.

From the tools of measuring weight:

kilogram. double pans balance.

Newton. spring balance.

The weight of a body its mass 200 gm on earth surface nearly equals:

2 Newton. 20 Newton.


The Newton is nearly equals weight of a body its mass:

1 gm. 10 gms.

100 gms. 1000 gms.

The mass of half liter of water equals:

5 gms. 50 gms.

500 gms. 5000 gms.

The weight of a person in a balloon at certain height from earth surface equals 70 Newton, what is the weight of the person on earth surface?



Which of the following is faster in conducting heat?

aluminum. iron.

copper. glass.

From the substances which are bad conductor of heat:

iron and aluminum. copper and glass

glass and wood. aluminum and copper.

GGe

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First Term

87

The operation of thermometer depends on the idea of:

The change of gases volume with the change in temperature.

The change of liquids volume with the change in temperature.

The change of gases mass with the change in temperature.

The change of liquid mass with the change in temperature.

The clinical thermometer is different from Celsius thermometer in:

The type of matter present in the reservoir

The presence of constriction in the capillary tube

The type of matter used in manufacturing

The effect of change temperature on the present liquid volume

All the following from the properties of mercury as themometrical substance except:

good conductor of heat.

its expansion is regular.

give limited extent to measure the temperature.

not adhere to the walls of capillary tube.

Which of the following gases have great percentage in atmospheric air:

oxygen. nitrogen.

carbon dioxide. water vapour.

Oxygen is present in the atmosphere in gas state in form of molecules ,its structure:

O. O2.

O3. O4.

Respiration and combustion processes consume ……….. gas:

oxygen. nitrogen.

argon. carbon dioxide.

Hydrogen peroxide decomposes in presence of manganese dioxide to:

oxygen and hydrogen. oxygen and water.

hydrogen and water. hydrogen and manganese.

Gene

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88

When a glowing magnesium ribbon is placed in a gar contains nitrogen gas then adding a little of water ………. gas evolves:

oxygen. nitrogen.

ammonia. hydrogen.

Which of the following can be obtained on adding dilute hydrochloric acid to calcium carbonate powder?

nitrogen. oxygen.

hydrogen. carbon dioxide.

All the following are from the constituents of the brain except:

two cerebral hemispheres. cerebellum.

medulla oblongata. spinal cord.

Which of the following is responsible for keeping the body balance?

medulla oblongata. two cerebral hemispheres.

spinal cord. cerebellum.

Medulla oblongata is responsible for:

controlling the voluntary movement. keeping the body balance.

controlling the involuntary processes. reflex action.

Which of the following joints is limited movement?

shoulder. wrist.

ankle. elbow.

Second: essay questions: A piece of rock is placed in a pan of double pans balance, the sum of masses which are placed in the other panis 300 gm to make balance.

• Answer the following:

What is the mass of the piece of rock? What the direction of the effect of this mass?

What is the weight of the piece of rock? What the direction of the effect of this weight?

What is the effect of changing the place on both mass and weight of the rock piece?

General questions on science – first termGGe

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First Term

89

Mention one function for each of the following:

Skull.

Theoretic cage.

The two cerebral hemispheres.

Spinal cord.

The vertebral column.

Explain the following:

In the clinical thermometer there is a constriction in the capillary tube above mercury reservoir.

The clinical thermometer is not used to measure boiling point of water.

The mercury is used in manufacture of thermometers.

Ozone layer has great importance in the life of creatures on the earth Surface.

The mass of aluminum wire increases after heating till it becomes red.

A white precipitate is formed when carbon dioxide gas passed in clear lime water.

Nitrogen is used in filling cars and airplanes’ tires.

What would happen in the following cases?

Nitrogen is not present in the atmospheric air.

The percentage of carbon dioxide gas increases in the atmospheric air.

A glowing magnesium ribbon is placed in a gar filled by carbon dioxide gas.

There are no joints in the skeleton.

The knee joint becomes from wide movement joints.

Continuous exposing to the noise.

The over use of stimulation drugs.

Abuser de prendre les matières stimulantes.

How to obtain:

Ammonia from atmospheric air.

Carbon from calcium carbonate.

Oxygen from hydrogen peroxide.

Gene

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Exam (1)

Exam

(1) Exam (1)

90

Complete the following statements: The human skeletal system consists of ................ and .................

The ................ is the measurement unit of mass whereas the ................ is the measurement unit of weight.

The ................ thermometer is used to measure the water temperature.

Put a (✔) or a (✘) in front of the following statements and correct the false ones:

In the spinal cord, there are centers responsible for sensory and kinetic responses. ( )

Mass is the force of earth’s gravity to an object. ( )

Sodium is used in the manufacture of the filament of the electric lamp. ( )

Heat transfers from a cold object to a hot object. ( )

Mention the function of: Cartilages between the vertebrae of the backbone.

Nerves.

Mercury in the medical thermometer.

Plastic in the manufacture of the handles of cooking utensils.

Give reason for the following: The rib cage surrounds both the heart and the lungs.

The force of the moon’s gravity is lesser than the Earth’s gravity.

The light bulb contains the argon gas.

First Term

Exam

(1)

91

What happens if: All the bones of the human body are without joints?

When you put your hand suddenly on a hot surface?

We get rid of soil bacteria?

Write the scientific term for the following statements: A system responsible for integration and coordination between systems of the human body.

A device used to measure the mass of objects.

Materials that let heat flow through.

An organ responsible for the reflux actions of the body.

Materials that do not let heat flow through.

Mention some precautions on dealing with electricity.

92

Exam

(2) Exam (2)

Exam (2)Question one:A - Choose the correct answer:

All the following from the components of central nervous system except:

Spinal nerve. two cerebral hemisphere.

Spinal cord. medulla oblongata.

The weight of the body on earth surface 6 Newton ,so its weight on moon surface equals:

1 kgm. 1 Newton.

6 kgm. 6 newton.

All the following from substances which are good conductors of heat except:

Aluminum and iron. copper and iron.

Glass and wood. Aluminum and copper.

The gas which is used with acetylene in welding metals is ……....… gas.

Oxygen Nitrogen

hydrogen carbon dioxide

When a glowing magnesium ribbon is placed in a jar containing carbon dioxide, on the walls of the jar, the element formed is:

Oxygen. Nitrogen.

hydrogen. carbon dioxide.

Question two:A - Explain the following:

There is a restriction in the capillary tube above mercury reservoir in clinical thermometer.

The mercury gives wide range to measure the temperature.

During oxygen preparation the gas is collected by down displacement of water in the jar.

Nitrogen gas is used in the atmosphere of the stores of explosive liquids.

It is essential to heat healthy food which is reach in calcium and phosphorus.

First Term

93

Exam

(2)

Question three:A - What would happen in the following cases:

There is no oxygen in the atmospheric air.

When the shoulder joints becomes from the limited movement joint.

Drinking big quantities of soft drink.

B - Mention one function for the following: Joints.

nervous system.

Question four:A - Explain ,how to obtain each of the following:

Nitrogen from atmospheric air.

carbon dioxide from calcium carbonate powder.

B - Mention one function for the following : Cerebellum.

Clinical thermometer.

Nitrogen gas.

Question five :A - Correct the following statements:

Copper from substances which the heat cannot pass through it.

The joints of the skull are from limited movements joints.

As the weight of the planet increases the weight of body on it decreases.

Oxygen gas not burn and not help burning.

Carbon dioxide is from the component of explosives.

94

Exam (3)

Exam

(3) Exam (3)

Question one:A - Choose the correct answer Choose the correct answer

If the weight of a body is 20 Newton , its mass equals:

2 Kg. 20 Kg.

200 Kg. 2000 Kg.

From the measuring units of weight:

Gram. litre.

Newton. Kilogram.

The maximum and minimum graduation of the clinical thermometer is between:

35 : 42 coleus degrees. 35 : 45 coleus degrees.

32: 42 coleus degrees. 32 : 45 coleus degrees.

Carbon dioxide gas is used in:

Steel industry . Le nitrogène.

Ammonia industry. Yeast industry .

Which of the following is from …….. joints:

Femur. wrist.

ankle. knee.

Question two:A - Mention one function for each of the following:

Spinal cord.

Spring balance.

B - Write the scientific term for the following: A tool used to measure body weight.

A gas used in photosynthesis process.

Spontaneous response from the body to the different stimuli.

First Term

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Exam

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Question three:A - Correct the following statements:

The weight is constant amount changes as the location changes.

Carbon dioxide gas is essential to form rust.

A black precipitate is formed when carbon dioxide gas is passed in lime water.

Nitrogen gas is used in putting off fires.

Question four:A - What would happen in the following cases:

All substances, that the man uses are good conductor of heat.

A nail wetted by water is exposed several day to humid air.

A man is exposing to noise continuously.

B - Write the scientific term: The amount of matter that the body contains.

The center of main control in human body.

a tool used to measure human body temperature.

Question five:A - Write one difference between:

Wide movement joints and limited movement joints.

Oxygen gas and nitrogen gas.

mass and weight.

B - Explain by using labeled diagram: Preparation of oxygen gas in the lab?.

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Exam (4)

Exam (4)Ex

am (4

)

First Question: objective questions:- Complete the following statements:

The mass is measured by ................ Unit and the weight is measured by ................unit.

From the examples of substances which are good conductors which are good conductors of heat ................ and .................

The clinical thermometer is graduated from ................ to .................

Oxygen is produced from ................ process and carbon dioxide produced from ................ process.

The number of nerves in human body is .................

The axial skeleton in the man consists of ................, ................ and .................

Second Question: Choose the correct answer: The thoracic cage in the man consists of ................ Pairs of ribs.

10. 11.

12. 13.

The part which is responsible for keeping human body balance is:

Two cerebral hemispheres. Cerebellum.

Medulla oblongata. Spinal cord.

The gas used to fill some types of lamps is:

Oxygen. Ozone.

Nitrogen. Carbon dioxide.

Photosynthesis process in the plant depend on the presence of:

oxygen. nitrogen.

carbon dioxide. ozone.

The weight of the body is measured by ................ balance.

spring. sensitive.

double pans. all the previous.

First Term

97

Exam

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The best metal in conducting heat is:

Aluminum . copper.

iron. wood .

Third Question: Write The Scientific term: The amount of matter that the body contains .

Tools used to measure the temperature .

A gas used to put off fires .

A gas molecules consists of three atoms of oxygen .

A part of nervous system responsible for reflex action .

The location of bones touch and allow moving .

Fourth Question: Give reasons for the following : The yeast is added to dough .

The infection of medulla oblongata lead to death .

Aluminum is used in manufacturing of cooking pans .

98

Exam (5)

Exam

(5) Exam (5)

First Question: - Complete the following statements :

From the examples of substances which are bad conductor of heat ................ and .................

The number of vertebrae of vertebral column is .................

The number of cranial nerves is ................ And the number of spinal nerves is .................

The holder of cooking pans is made of .................

The mass is measured by ................ balance and the weight is measured by ................

balance.

Oxygen is prepared from ................ in presence of .................

Second Question: Choose the correct answer: The gas which turn lime water turbid is ................ gas.

Oxygen. Nitrogen.

Carbon dioxide. Ozone.

Nitrogen is used in manufacture of:

Fire extinguisher. Fertilizers.

Soft drink. dry ice.

Your weight on earth surface is 600 Newton so your weight on moon surface is ................ Newton:

6 60.

100 10

The centers of thinking and concentration lie in:

Medulla oblongata . spinal cord.

cerebellum. two cerebral hemi spheres .

The weight of the body is measured by ................ balance.

Knee Femur

elbow all the previous

First Term

99

Exam

(5)

Hydrogen peroxide is used in preparation of:

Hydrogen. Oxygen.

Nitrogen. Carbon dioxide.

Third Question: Write The Scientific term : The attraction force of the earth to the body.

A flame used in cutting and welding metals.

A gas used in ammonia industry.

The center of the main control in human body.

Ligaments ties muscles with bone.

Areas between vertebrae of vertebral column separate and protect from friction between them.

Fourth Question: Compare between each of the following: Mass and weight.

Clinical thermometer and Celsius thermometer.

Central nervous system and appendicular nervous system.

100

Complete the following statements: Kilogram – Newton.

Aluminum – Copper.

35 ̊C – 42 ̊C.

Photosynthesis process – Respiration.

12 pairs.

Skull – back bone – rib cage.

Chose the right answer: 3 12 pairs.

2 Cerebellum.

3 Nitrogen.

3 Carbon dioxide.

1 spring.

2 Copper.

Write the scientific term: Mass.

Thermometers.

Carbon dioxide.

Ozone.

Spinal cords.

Joints.

Give reasons for: (Answer by yourself)

Model answer exam (4)Mod

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exam

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Model answer exam (4)

First Term

101

Complete the following statements: Wood – plastic.

33 vertebrae.

12 pairs – 31pairs.

(Wood or plastic).

One arm scale – spring Scale.

Hydrogen peroxide – Manganese dioxide.

Chose the right answer: 3 Carbon dioxide.

2 Fertilizers.

3 100 Newton.

4 Cerebral hemispheres.

2 Femur.

2 Oxygen.

Write the scientific term: le poids du corps.

l’oxyacétylénique.

le nitrogène.

le cerveau.

les tendons.

les cartilages.

Compare between each one of the following: (Answer by yourself)

Model answer exam (5) Mod

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nsw

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exam

(5)

Exam (1)

102

A gu

ide

mod

el fo

r th

e st

eps

of th

inki

ng

of th

e st

uden

t to

reac

h to

the

solu

tion

Example: The weight of a body its mass 200 gm on earth surface nearly equals: 2 Newton.

20 Newton.

200 Newton.

2000 Newton.

The steps of thinking in this question to reach the solution: The student remembers that the weight of the body on earth surface depends on its mass.

The student write the following relation:

The weight in Newton = the mass in grams × 10

The mass is converted from gram to kilogram by dividing 200 gm over 1000 to obtain the body mass in kilogram (0.2 kgm).

The student substitutes in the previous relation as following:

The weight in Newton = 0.2 × 10 = 2 Newton

The student chooses the answer: (a) 2 Newton.

A guide model for the steps of thinking of the student to reach to the solution

A guide model for the steps of thinking of the student to reach to the solution

First Term

103

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e

Reference

بهذه االستعانة تم الكتاب، هذا إعداد عليه ارتكز الذي والتربوى العلمى التوجه ضوء بهذه في االستعانة تم الكتاب، هذا إعداد عليه ارتكز الذي والتربوى العلمى التوجه ضوء في المراجع:المراجع:

1 Cooney, T.; et al (2007). Science. Scott Forsman.

2 Dispezio, M.; et al. (2008). Science Insight - Exploring Living Things. Scott Forsman - Addison Wesley.

3 Dispezio, M.; et al. (2008). Science Insight - Exploring Matter and Energy. Scott Forsman - Addison Wesley.

4 Exline, J. D. (2008). Science Explorer - Earth’s Changing Surface. Prentice Hall.

5 Perfect Match Science, Pearson Education.

6 Fundamentals of Physics. D.Halliday, R.Rensick, J. Walker Publisher: J. Wiley, 1993.

ûأنشطة إبداعية في العلوم للمرحلة االبتدائية، المركز القومى للبحوث التربوية بالتعاون مع هيئة التعاون الدولية اليابانية ( الجايكا).

ûكتاب المعرفة فى جسم اإلنسان، موسوعة سؤال وجواب فى جسم اإلنسان، مهرجان القراءة للجميع، مكتبة األسرة.

ûكتاب الصوت والضوء، سلسلة القراءة للجميع، مكتبة األسرة.

ûموسوعة الشباب فى المعلومات - د. عبد الباسط الجمل.

ûالكتاب الكبير عن الفضاء والمكان، وليم أدهورز.

ûالموسوعة العلمية الشاملة - مكتبة لبنان ناشرون - بيروت.

ûأساسيات الفيزياء / تأليف: ن. بوش.

ûموسوعة العلماء والمخترعين / إعداد: د. إبراهيم بدران - د. محمد فارس.

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