Science 2nd Term Q and A

8/15/2019 Science 2nd Term Q and A

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Science Junior four ( Second Term )

Digestion: changing the food from a complex form into a simple

one to let the body get benefited.

[1] Mouth

Salivary glands: They are three pairs of glands secreteliquid known as the saliva which contains digestive

substances called enzymes that digest starches then

convert them into simpler substances known as sugars.

Tongue: mixes food with saliva helps in swallowing food.

Teeth: the teeth number in an adult are !"

each #aw has $% teeth divided into

&' incisors "canines and $( molars).

Digestive System

Digestive canal Digestive canalsupplementaries

Salivary

glands

Liver Pancreas

Mouth Pharynx

Esopha-gus

Stomach

Smallintestin

e

Largeintestin

e


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0bsorption: Digested food is absorbed through the small

intestine walls then it reaches blood which distributes it all

over the body organs.

[] !arge intestine"Starts from the end of small intestine and ending in the anuswhich is located at the end of the rectum.

#eeping the Digestive System $ealthy"

$. 1hew the food well

". Don2t eat much food that contains large amounts of fats.

!. Stop having food containing the additive.

'. Stop purchasing food from streets to avoid infectious

diseases.3. 4ractice sports.

%uestion one"

$. Digested food is absorbed in the555555555

a) esophagus b) stomach

c) small intestine d) large intestine

". Starches digestion starts by the555555555a) gastric #uice b) intestinal #uice

c) saliva d) bile

%uestion t&o"

6igure &0) shows a part of the digestive system known

as555555555555


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Structure o' (espiratory System

7espiratory system contains of the nose pharynx trachea the

two bronchi and the two lungs.

[1] )ose+t2s lined with a mucus large and hair to filter air from dusts and

blood capillaries to warm air.

[2] Pharynx0 common cavity leads to the esophagus and trachea.

[3] *rachea- +t has cartilage rings to keep it open all the time.

- +t has cilia to e#ect up strange ob#ects.

- 0t the top of trachea there is larynx &voice box) and

epiglottis which closes trachea when swallow food.

[4] !ungs+nside it there is alveoli surrounded by

0 net work of blood capillaries to permit gas exchange.

+ (espiration" is the process in where the air rich in oxygen

enters into the two lungs and the air rich in carbon dioxide

released outside the two lungs.

* The more active your body is the more your respiration times

increases.

+ Exchange o' gases


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8xchange of gases occurs between the air existed in alveoli and

the blood flows in the capillaries via their thin walls where blood

leaves carbon dioxide and carries the oxygen and distributes itall over the body cells.

Exhalation air contains car,on -ioxi-e an- &ater vapour as

pro-ucts o' respiration process.

#eeping the respiratory system healthyTo keep your respiratory system healthy you should stick to the

following:

$. Stop being in crowded places.

". 9eeping off the severe cold.

!. aving fruits rich in vitamin &c) such as oranges guava to

protect yourself from cold.

'. Stop smoking.


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+ *he cell is the ,uil-ing unit o' the living organism ,o-y.

/ *he cell simpli'ie- structure0ll cells are units contain:

$. -ucleus: organizes the biological operations inside the cell.

". 1ytoplasm: fill the space and helps biological operation.

!. 4lasma membrane: surrounds the cell and controls the

substances entering into the cell or leaving it.

+ 0omparing a plant cell to an animal cell

1ell parts 4lant cell 0nimal cell$* 1ell wall

"* 1ell membrane

!* nucleus'* 1ytoplasm

3* 1hloroplast

The plant cell than the animal one is characterized by the

presence of a cell wall surrounding it and contains chloroplasts

which are responsible for making food in a process known as

photosynthesis.


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/ 0ell is the unit o' structure in a living organism.

/ 0ell is the unit o' 'unction in a living organism.

+ nicellular organisms"

There are a lot of unicellular micro*organisms around us which

can2t be seen by the naked eye as bacteria and yeast.

* Structure of yeast fungus: it is a unicellular living organismthat made up of nucleus cytoplasm and a wall that determines

the cell shape. The fungus has a great economic value.

/ Economic importance o' the yeast 'ungus" se- to"

$* ;aking bread. "* ;aking alchohol.

0ells *issues rgans Systems

utrition7espirati*

on


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Plants manu'acture their 'oo-

4lant cell contain chloroplasts which give the plants the green

color and absorb sunlight as well.

4lants absorb the light energy of the sun water and salts fromthe soil and carbon dioxide from the air in order to form their

food this process is known as photosynthesis.

Sunlight light energy is necessary 'or plants to mae their

o&n 'oo-. 6urthermore7 sunlight is consi-ere- as the resource

o' energy 'or plants.


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4lant &0) grows

&/) The covered plant becomes yellowish and weak this is related

to the absence of sunlight and the plant stopped manufacturingits food.

* Pro-ucers: are living organisms that can make their food.

Examples o' pro-ucers"

xygen


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+ 0omplete"

$. trachea has5555555555 rings to keep it open all the time.

". 555555555555is a muscular sac mixing food with gastric

#uice.

!. 5555555555and5555555555 ate at the top of trachea.

'. 55555555555is the process of entering oxygen into two

lungs and releasing carbon dioxide outside the two lungs.3. 55555555555is a common cavity between the digestive

system and the respiratory system.

%. Trachea contains55555555555which e#ect up the strange

ob#ects.

?. The cell contains555555555555 555555555555and

plasma membrane.

@. -ose is lined with a55555555555555layer.A. The tissue is a group of55555555555555

+ 8hat is meant ,y"

$. Digestion.

". 7espiration.

!. 0bsorption.

+ 8rite the 'unction o'"

$. -ose.". 1ilia in the trachea.

!. 8piglottis.

'. Small intestine.

3. /ile #uice.


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1] 0omplete"$. The animal cell is surrounded by5555555555while the

plant cell is surrounded by55555555555

". 8ach of the animal cell and plant cell has55555555555

55555555555and55555555555

!. Tissue contains of a group of55555555555

'. The555555555cell is characterized by the presence of

cellular wall.3. The building unit of a living organism is celled555555555

%. 5555555555is an example of unicellular living organism.

2] 0ompare ,et&een the plant cell an- the animal cell.

3] !oo at the 'ollo&ing 'igure an- &rite the part9s

names.

4] 8hat is the 'unction o' each o'"

$. 1ell wall.

". -ucleus.

!. 1ytoplasm.

'. 4lasma membrane.


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Progress sheet (1)

Complete :

$* the digestive system consists of 55555..and 5555555."* digestion is changing the food from 555. 6orm into

5555.form

!* digestive canal supplementaries are55..555.and 555555

'* number of salivary glands are 5555and they secrete 5555.

3* number of teeth is 5555divided into 5...teeth in each #aw

Write down the scientific term :

$* +t mixes the food with saliva & )

"* They cut and tear the food into small pieces & )

!* 1hanging the food from a complex form into simple form

& )

Write down the function of each of the following:$* molars :5555555555555

"* salivary glands :55555555555..

!* incisors and canines:55555555555


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0 lot of animals depend on plants to get their food where plants

supply animals with the required energy for survival.

Examples"

$* 1ows or sheep feed on plants.

"* /irds feed on the seeds of some plants.

* *his means that: The plant is the main source of food andenergy for man and most of animals.

* /ut how does the plant obtain &manufacture) its foodB

The green plant makes its own food by photosynthesis process in

its green leaves as they contain chloroplasts. So the green plant

is called a pro-ucer organism.

+ Photosynthesis process"

0 biological process takes place in the green parts &leaves) of theplant to make its own food &carbohydrate which is sugar or

starch) in the existence of sunlight water carbon dioxide gas

and some mineral salts and oxygen gas is released &evolved).

+ *he necessary 'actors 'or the photosynthesis process"$* Sunlight. "* 1hloroplasts.

!* 1arbon dioxide gas &produced from respiration).

'* Cater and mineral salts./ *o pro-uce"

$* Starch or sugar &carbohydrate).

"* >xygen gas &needed for respiration).

+ $o& -oes the plant mae its o&n 'oo- ,y

photosynthesis process:$. The green leaves of the plant absorb sunlight by chloroplasts

which give the plant its green colour. ". The plant absorbs water and mineral


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salts from soil through roots that transport them to the stem

then to the leaves.

!. 4lant leaves absorb carbon dioxide gas from air.

'. 0ll the previous substances react together to produce theplant food &starch or sugar) and oxygen gas.

☺;ctivity 1" To prove the importance of sunlight in thephotosynthesis process of green plants.

/ Steps"

$*/ring two flower pots &0E/) each one contains a green plant.

"*1over plant &/) by a paper sac with narrow holes to let the

air pass.!*eave the two flower pots for two days and water them

regularly.

/ ,servation"

The leaves of plant &/) are yellow and weak but the leaves of

plant &0) are green and strong.

/ 0onclusion"

Sunlight &light energy) is necessary for plants to make their ownfood. So the sun is the main source of energy for plants.


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it in ethyl alcohol to get rid of its

green colour &chloroplasts) as in fig.&b).

/ ,servation"

The green colour of the leaf changes into yellow.

!* Cash the leaf gently with water

0s in fig.&c) then put some drops of

iodine solution on it &to check the

presence of starch) as in fig.&d).

/ ,servation"The leaf will be coloured blue due to the presence of starch.

/ 0onclusion"

4lants make their own food &starch) by the photosynthesis

process.

☺;ctivity 3" To prove that oxygen gas is released &a product)from the photosynthesis process.

/ *ools" 0 glass container , 8lodea plant , 0 glass funnel , 0test tube , Sodium bicarbonate.

/ Steps"

$. Dissolve sodium bicarbonate in the

glass container containing water &to

obtain carbon dioxide gas needed

for the photosynthesis process).

". 4ut a sample of an aquatic plant&elodea plant) in the container and

invert a glass funnel above it.

!. +nvert a test tube filled with water over the funnel neck.

'. 8xpose the apparatus to sunlight for few hours to allow the

plant to perform the photosynthesis process.

/ ,servation"

The level of water in the test tube falls down and air bubbles areformed.


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3. 1lose the test tube mouth with your finger and remove it from

the container.

%. Turn up the test tube in the right way.

?. ight a splint and close it to the test tube mouth./ ,servation"

The glowing of the splint increases indicating the presence of

oxygen gas which helps in burning.

/ 0onclusion"

>xygen gas is released during &a product of) the photosynthesis

process.

>xygen gas helps in burning.

+odine solution is used to test the presence of starch in

a plant where its colour turns into blue.

Sodium bicarbonate provides water with carbon dioxide

gas which is required for the photosynthesis process.


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The rot is formed by some living organisms &such as fungi)that

are called decomposers as they decompose food.


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@. 55555555and555555555are examples of consumers that

feed on consumers that previously fed on producers.

A. The living organisms which are responsible for decomposing

the remains of the living organisms are known

as5555555555

2] 0hoose the correct ans&ers"

$. The photosynthesis process takes place in the5555555of

the plant.

a) roots b) green partsc) seeds d) all the previous answers

". 0ll the following are necessary for photosynthesis process

except555555555

a) carbon dioxide gas b) starch

c) water d) sunlight

!. 4lants use55555555in the photosynthesis process.

a) oxygen gas b) nitrogen gas

c) carbon dioxide gas d) water vapour

'. 555555555is one of the products of the photosynthesis

process in plants.

a) -itrogen gas b) >xygen gasc) 1arbon dioxide gas d) Sunlight

3. 55555555are examples of producers.

a)


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?. /read mold fungus is a555555555

a) producer b) decomposer

c) consumer d) all the previous answers

3] Put √ in 'ront o' the correct statement an- × in

'ront o' the &rong one7 then correct it"

$. 4lant makes its own food by the respiration process. &

)

". Starch and oxygen gas are produced by the plant through

the respiration process.& )

!. >xygen gas is essential for the photosynthesis process. &

)

'. The products of the respiration process of plants are

different from those of the photosynthesis process.

& )3. Ce use sodium bicarbonate solution to absorb oxygen gas

from water.

& )

%. ion snake and hawk are consumers that feed on producers.

& )

?. /read mold fungus and some types of bacteria are examplesof decomposers.

& )

4] 8rite the scienti'ic term 'or each o' the 'ollo&ing"

$. The products of the photosynthesis process.

". iving organisms that can make their own food by the

photosynthesis process.

!. 1ows sheep and chicken.


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5]


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3. Decomposers which depend on organic remains Adead bodies

of consumers or producers) on feeding so they help the

environment to get rid of the remains of those bodies.

*here'ore"There are food relations between all living organisms.

8here"

*


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* 7abbit feeds on green plant so it is a herbivorous consumer.

* Snake feeds on rabbit so it is a carnivorous consumer.

* awk feeds on snake so it is a carnivorous consumer.


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3.


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1] 0omplete the 'ollo&ing sentences"$. The living organism which makes its own food is known

as55555555

". 5555555555feed on organic remains.

!. 6ood chain begins with5555555555 the herbivorous

consumer then5555555555

'. uman beings are considered as55555555in the food

chain.3. 55555555is a group of overlapping food chains

representing the flow of energy through living organisms in

the form of food.

%. The producer gets the solar energy from5555555555

?. 55555555is known as the energy transference from a

living organism to another.

2] 0hoose the correct ans&er"

$. The living organisms are classified into55555555according

to their feeding.

a) consumers b) decomposers

c) producers d) &a) &b) and &c)

". 5555555depend on themselves to make food.

a) green plant b) consumers

c) green algae c) &a) and &c)

!. +n the food chain that contains green plant locust and

snake locust is considered as a55555555

a) producer b) herbivorous consumer

c) decomposer d) carnivorous consumer

'. The path of energy in a form of food through living

organisms is known as55555555

a) food chain b) food web

c) consumer d) &a) and &b)


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3. ion can be classified as a555555555

a) carnivorous and producer b) decomposer and consumer

c) carnivorous and consumer d) decomposer and

herbivorous%. The last consumer in the food chain is the555555555

a) producer b) carnivorous

c) herbivorous c) all the previous answers

?. +f you have a food chain that contains of rat owl snake and

green plant the correct path of food is555555555

a) snake green plant owl rat.

b) green plant owl rat snake.

c)


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!. 1hicken is a herbivorous consumer. &

)

'. 6ood chain starts with a producer organism. &

)3. The following order is the right order of a food chain:


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2. 4ut a toy car on the table and push it towards your

classmate.

/ ,servation"

The toy car moves towards your classmate &becomes at motionstate).

!. 0sk your classmate to put his hand on the way of the toy

car.

/ ,servation"

The toy car stops its motion &becomes at rest state).

/. ;otion of a bicycle and its rest.

/ Steps"

$. Try to ride a bicycle and move it.

". Try to stop the bicycle.

/ ,servation"

$. The bicycle moves by pushing its pedals.

". The bicycle stops when you press on the brakes.

/ Explanation"

* /efore riding the bicycle it was at rest.

* Chen riding the bicycle leg pushing force pushes its pedals

and changes its state from rest to motion.

* Chen you press on the brakes brakes stopping force

changes the state of the bicycle from motion to rest.

/


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+t is the effect that change is -ewton related to the scientist.

Application on using force in our daily life

1]


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• ;ll the previous machines contain"

* 4ulleys that make the motion easy.

* b#ects need555555555to change its state.

". 4ushing force is needed to change the state of an ob#ect

from 5555555555to555555555

!. 55555555force changes the state of a toy car from rest

to motion.

'. The measuring unit of force is555555555related to the

scientist555555555

3. 5555555555is needed to rise the heavy ob#ects.

%. 5555555and55555555are examples of technological

applications that depend on engine pushing force.


$. 6orce is an effect which changes the555555555

a) motion of the ob#ect b) state of the ob#ect

c) rest of the ob#ect d) all the previous

answers

". 6orce is measuring by55555555unit.

a) -ewton b) kgGm c) km d)

mGsec

!. Sailing boats move on the surface of the 7iver -ile by the

555555555pushing force.


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a) water b) wind c) ropes d)

motor

'. 555555555is one of the applications that depend on

engine pushing force in motion.a) ;etro b) electric lift

c) bicycle d) electric sewing

machine

3. 8lectric fan rotates by the effect of55555555555force.

a) water pushing b) air pushing

c) motor pushing d) hand pushing

3] Put √ in 'ront o' the right statement an- × in 'ronto' the &rong one"

$. and pushing force changes the state of a toy car from

motion to rest.

& )

". 9ite flies by the effect of air stopping force. &

)

!. 6orce is needed to move ob#ects not to rise heavy ob#ect. & )

'. /lender washing machine and electric sewing machine

depend in their motion on the effect of force.

& )


$. The effect that changes the state of the ob#ect.". ome equipment depend on motor pushing force in motion.

!. The force that train and car depend on.

'. 4arts existing in the machine to make the motion easy.

5] 0orrect the un-erline- &or-s"

$. Time is an effect that causes the change in the state of an

ob#ect.

". 9ilogram is the measuring unit of force.!. Stopping force causes the motion of ob#ects.


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'. +n machines pulleys are used to make transfer motion.

3.


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+ Soun- energy"Soun-" it is a form of energy that reaches ear causing hearing.

☺ ;ctivity" To learn how is sound produced.;

/ Steps"

$. 6ix one end of a plastic ruler on a wooden table.

". 4ull the other end of the ruler downwards then leave it.

/ ,servation"

The ruler vibrates and produces sound.

@/ Steps"

$. 1atch a tuning fork from its handle and tap it on a wooden

table.

".


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/ ,servation"

Fou feel the vibration of its two prongs.

/


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$. +n a toy car the5555555energy changes into5555555

energy.

". 5555555energy changes into sound energy in the guitar.

@/ 0hanging o' inetic energy into heat energy"☺ ;ctivity" to prove that the kinetic energy changes into heatenergy.

/ Steps"

7ub your hands together.

/ ,servation"

Four hands feel worm.

/ 0onclusion"The kinetic energy of your hands changes into heat energy.


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☺ ;ctivity" To prove that the light energy changes into heatenergy.

/ Steps"

$. 4ut the convergent lens over the paper at a fewcentimeters.

". 8xpose the lens to sun rays for a period of time to focus

these rays at a point of the piece of paper.

/ ,servation"

The piece of paper will heat up and it may burn if it is exposed to

sun rays for a long period.

/ 0onclusion" The light energy changes into heat energy.@/ 0hanging o' light energy into electric energy"Example" The solar cells.

+ *he ,ene'its o' the solar cell"$. +t changes the light energy into electric energy.

". +t provides the satellites by the electric energy to operate

their equipment.

!. +t generates the electric energy that is used in homes.6rom the previous explanation7 &e conclu-e that the

energy changes 'rom one 'orm into another in many

e>uipments as in the 'ollo&ing ta,le"

). e>uipment se- energyPro-uce-

energy

$ 8lectric fan 8lectric kinetic

" 8lectric lamp 8lectric ight

! 8lectric heater 8lectric eat

' 7adio 8lectric Sound

3 Dynamo kinetic 8lectric

% 8lectric motor 8lectric kinetic

? Hiolin kinetic Sound

@ Solar cell ight 8lectric

A Solar heater ight eat


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$( /attery 1hemical 8lectric

1] 0omplete the 'ollo&ing statements"

$. 8nergy is the ability to do5555555

". 555555..555555and5555555.are forms of energy.

!. Sound originates from55555555

'. +n the violin the kinetic energy can change into55555

energy but when you rub your hands together5555555energy changes into5555555energy.

3. 555555energy changes into5555555energy during

knocking on the door.

%. +n the electric lamp the electric energy changes

into5555555 energy.

?. Ce get5555555energy from the solar cells.

@. +n solar cells the energy produced is5555555.energywhile in the solar heater the energy produced is5555555

energy.


$. The kinetic energy changes into sound energy in55555555

a) violin b) knocking on the door

c) the electric fan d) &a) and &b)

3] Put √ in 'ront o' the right statement an- × in 'ront

o' the &rong one"

$. >n riding a bicycle you need energy. & )

". 8lectric energy sound energy and light energy are from the

forms of energy. & )

!. The energy produced from the solar heater is electric energy.& )

'. Sound stops when the vibration of a tunning fork stops.& )


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3. The electric energy changes into light energy in the electric

lamp. & )


$. +t is the ability to do work.

". The energy produced from the dry cells.

!. 0 form of energy that is produced from the vibration of

ob#ect.'. The energy used in the dynamo and the violin.

3. The energy produced from rubbing your hands together.

5] n removing a nail from a wooden plate the nail becomes

warm.

] 8hat is the 'orm o' energy tat is pro-uce- 'rom"

$. 7otation of the dynamo.

". 9nocking on the door of a classroom.

!. 4assing of the electric current through an electric lamp.

'. 7ubbing your hands together.3. 7inging of a school bell.

%. 7unning of a pupil.

=] Mention the changes o' energy in the 'ollo&ing cases"

$. 0 moving bicycle containing a lamp.

". ighting of an electric lamp in your classroom.

B] 8hat happens &hen"$. Sun rays fall on a lens that is put over a piece of paper.

". 0 piece of fixed rubber is pulled then is left.


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!. Fou remove a nail from a wooden plate and why.

* Solar energy is the cleanest form of energy.

@ut7 8hat are the ,ene'its o' the solar energy:

1/ Ct helps plants mae their o&n 'oo-

* Fou know that if the plant is not exposed to the sun its

leaves become yellow then the plant dies as it can2t make

its own food.

* So solar energy &the sun) is necessary for growth of plants.

2/ Ct is necessary 'or other living organisms

* The sun &solar energy) provides some animals and humans&that feed on plants) with food as it helps the plant make

its own food.

* +t provides us with light and warmth &heat).

3/ 6ormation o' clou-s7 &in-s an- rain

;] 0lou-s"

* Cater in seas lakes and oceans evaporates by the effect of

the sun2s heat &solar energy) forming water vapour.

* Chen water vapour rises in the sky it cools and condenses

forming clouds.


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* So clouds are formed by evaporation and condensation

processes.

@] 8in-s"

The sun2s heat causes the difference in temperature in someareas so winds are formed.

1I 7ain:

* 1louds move by the effect of winds.

* Chen the volume of water drops in clouds increases and the

air can2t carry them so rain falls.

4/ 6ormation o' petroleum oil an- coal 'uel

The sun &solar energy) is responsible for the formation of

petroleum oil and coal.

5/ Machine operation

Some means of transport like cars are operated by benzene

&gasoline) which is extracted from petroleum oil &that is formed

by the effect of the sun).

/


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+t changes solar energy of the sun into heat energy that is used

in warming homes and heating water.

+ *he Sun" it is the main source of energy on earth.

Sources o' energy

$* 7enewable resources "* -on*renewable resources

1/ (ene&a,le resources o' energyThey are the resources of energy that renew themselves.

Examples"

$. Cind energy ". 7ising and ebb tides

energy!. Caterfalls energy

1. 8in- energy"

+t is used in rotating the windmills to generate electricity.

2. (ising an- e,, ti-es energy"

* Fou have studies in the unit of universe that the moon

causes the occurrence of rising and ebb tides.* The energy produced from rising of the level of sea and its

returning back is used in rotating turbines that operates

generators &dynamo) to produce electricity.

+ Machines an- rene&a,le resources o' energy"There are machines that are rotated by renewable resources of

energy as:

$. Cindmills that work by wind energy.". Turbines that work by waterfalls energy and rising and ebb

tides energy.

2/ )on/rene&a,le resources o' energyThey are the resources of energy that don2t renew themselves

and they may be exhausted by the continuous use.

Examples"

$. 1oal ". 4etroleum oil or its derivatives!. -atural gas


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+ )atural gas"+t is one of the cleanest forms of fuel because it causes less

pollution for the environment so the government exerts a great

effort to increase its production.


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%. Cindmills are used in55555555555

?. 7ising and ebb tides happen by the effect of5555555555


o' the &rong one"$. The sun &solar energy) provides us with light only. & )

". The plant grows in the presence of sunlight. & )

!. The motor of a car works y the natural gas or gasoline.& )

'. The sun is responsible for forming petroleum oil. & )

3. Cind is one of the non*renewable resources of energy.& )


$. The main source of energy on the 8arth2s surface.

". 0 device that changes the solar energy into electric energy.

!. The sources of energy that include coal petroleum oil and

natural gas.

'. The sources of energy that include wind energy rising and

ebb tides energy and waterfalls energy.4]


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1. Static electricity"+t is a type of electricity that is formed from electric changes

that remain on an ob#ect.

+ Some phenomena relate- to the static electricity$. The vision of light in the sky that is called lightning.

". Standing of your hair during combing it by a plastic comb.

(eason"

/ecause by rubbing your hair by a comb the electric charges are

formed on the comb and make your hair attracted to the comb.

(eason"/ecause during motion parts of your body are rubbed by the

clothes forming the electric charges on your body and clothes.

+ $o& can you generate static electricity:Ce can generate the static electricity by methods. >ne of them

is rubbing.

☺ ;ctivity" To prove that rubbing of a balloon generates static

electricity.

/ *ools"

0 balloon , 0 piece of wool , 0 little amount of powered sugar , 0

thread.

/ Steps"

$. /low a balloon and tie its opening by a thread.

". 7ub the inflated balloon by the piece of wool.

!.


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/ ,servation"

The balloon attracts the sugar.

/ Explanation"

>n rubbing the balloon by a piece of wool the balloon becomescharged where the electric charges are formed on its surface

causing the attraction between the balloon and sugar.

/ 0onclusion"

7ubbing of ob#ects generates static electricity.


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☺ ;ctivity" To form a model of an electric circuit./ *ools"

0 battery , 0 lamp with base , connecting wires with uncovered

ends , 8lectric switch./ Steps"

$. Set up an electric circuit as shown in the opposite figure.

2. 0pply the following steps then record your results in the

table.

/ ,servation"

The lamp lights when the circuit is closed and contains the

battery./ 0onclusion"

$. The electric circuit contains:

a) The battery that is the source of the electric current.

b) The switch that is used to close and open the circuit.

c) The connecting wires that:

* Jsed to connect all the circuit components together.

* Transfer the electric current from the battery to

lamp.

". To obtain an electric current the electric circuit must be

closed.

+ *he electric circuit"+t is the closed path of the electric current.


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!. 1onnect the two rods by the lamp across the wires.

/ ,servation"

The lamp lights.

/ 0onclusion"Ce can make a battery from some fruits as lemon.

+ 8hat happens &hen"

Ce put the zinc rod and the copper rod in an apple or potato or

orange or sweet potato then connect the two rods by a lamp

through wires.

* the lamp will light in all cases.

+ *he electric e>uipments that are operate- ,y the

current electricity use- at home"

$. Television.

". Cashing machine.

!. 1omputer.

'. Hacuum cleaner.3. 7ecorder.

%. eater.

?. 7efrigerator.

+ Metho-s 'or -ecreasing rationaliing the consumption

o' electricity"

$. Jse the solar cells to produce electricity from the solarenergy.

". Turning off the lamp when leaving a place.

!. Turning off all unused equipments.


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1] 0omplete the 'ollo&ing sentences"

$. 555555555is a clean form of energy.

". 55555555and555555555are from the phenomena that

are related to the static electricity.

!. 55555555is an electric current that flows in one direction.

'. The55555555is the source of the electric current in the

electric circuit.

3. The connection wires are used to transfer the55555555from 555555555to the lamp.


$. Types of electricity are5555555555

a) the static electricity only b) the dynamic

electricity onlyc) light and heat energy d) &a) and &b)

". 55555555is the type of electricity that is produced due

to the remain of the electric charges on a body.

a) static electricity b) electric circuit

c) dynamic electricity d) current electricity

!. Static electricity is formed by55555555ob#ects.

a) rotating b) pushingc) rubbing d) vibration

'. 55555555is the electric charges that flow through

connecting wires for long distances.

a) current electricity b) static electricity

c) electric circuit d) &a) or &c)

3. 9ey is used to555555555

a) close the electric circuit only b) open the electric circuit

only

c) cut the electric wires d) &a) and &b)


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o' the &rong one"$. 8lectricity is a clean form of energy. & )

". The only type of electricity is the static electricity.& )

!. The standing of hair during combing it with a comb is

related to the static electricity while the lightning in the

sky is related to dynamic electricity. & )

'. The current electricity can be generated by rubbing an

inflated balloon with a piece of wood. & )3. 8lectricity can be generated by a lemon a rod of zinc and a

rod of copper. & )

4]


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". 7ubbing a plastic ruler by a piece of wool.

!. 7emoving a battery from a closed electric circuit.

'. Fou put a copper plate and a zinc plate in a lemon the touch

them by your tongue.=] 8hat is the 'unction o'"

$. /attery.

". 1onnecting wires.

!. 8lectric switch &key).

Science 2nd Term Q and A

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