١

Unit (1) : Lesson one

Attempts of elements classification

Importance of elements classification:

1. Facilitate the study of elements.

2. Finding the relation of element's properties and their position.

• Mendeleev periodic table:

No. of known elements was 67.

He arranged elements ascending according to atomic weight.

• Advantages of Mendeleev's periodic table:

1. He corrected the wrong estimated atomic weights of some elements.

2. He left gaps (empty cells) as he predicted the discovery of new elements.

• Disadvantages of Mendeleev's periodic table:

1. He made disorder in arrangement in the ascending order of the atomic weight.

2. He had to put the element in more than one cell. ( he considered the isotopes of

elements as different elements)

• Moseley's periodic table:

1. He added zero group (noble gases).

2. He arranged elements ascending according to atomic no.

• Bohr discovered the main energy levels of the atom and their number reaches 7 in the

heaviest atom.

• Rutherford discovered that the nucleus of the atom contains protons.

• Modern periodic table:

1. Their atomic numbers.

2. The way of filling of energy sublevels.

3. Formed of 7 horizontal periods and 18 vertical groups.

4. Formed of 4 blocks (s- block, p- block, d- block, and f- block).

• Location of elements in the modern periodic table:

1. Element’s period no. = no. of energy levels in the element.

2. Element’s group no. = no. of electrons in the outer energy level.

Cairo Governorate

Nozha Directorate of Education

Nozha Language Schools

Ismailia Road

Department : Science Form : 2

nd prep

Revision sheet

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Unit ( 1 )

Lesson (1) : Attempts of elements classification

I- Complete the following

1. Elements of block “d” are called ……………and they appear starting from

……….period

2. The group number of the element indicates the number of ………… while the period

number equals to ………………….. that occupied by electrons .

3. Mendeleev arranged the elements of similar properties in ………………..

4. The number of elements in Mendeleev’s periodic table is …………………….

5. Moseley classified the elements in an ascending order according to their

……….……

6.The modern periodic table consists of ……………periods and ………..groups

7. ………….and …………….occupy a place below the periodic table of

Moseley .

8.The positively charged particles found inside the nucleus are ……………

9. Mendeleev classified the elements according to ……………….

10. Lanthanides and actinides are located in ………………..

11. Elements of “ p “ block are arranged in ……………..groups .

12. The atomic no. of an element that is found in period 3 group 1 A is …………

II- Write the scientific term :

1. He added group zero to the periodic table . [ ]

2. The horizontal rows in which elements are arranged in an ascending .

[ ]

3. An element exists in period 2 and group zero . [ ]

4.The scientist how corrected the atomic weights of some elements which were

estimated wrongly . [ ]

5. The block of elements which is located on the left side of the periodic table .

[ ]

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III- What is the scientific principal upon which the elements are arranged in the

modern periodic table

…………………………………………………………………………………….

……………………………………………………………………………………

IV- Give reason for

1.The scientist Mendeleev had to put in one place of his table more than one element

…………………………………………………………………………………….

……………………………………………………………………………………

2.Scientists classified the elements in tables .

…………………………………………………………………………………….

……………………………………………………………………………………

V- Locate the position of the following elements :

a) Si 14 ……………………………………………………………………………

b) Ne 10 ……………………………………………………………………………

c) K 19 ………………………………………………………………………………

K L M

- What is the atomic no of the element

- That follows this one in period , in group

2 8 1

+11

± 12

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Lesson 2

Graduation of elements properties in the modern periodic table

� Properties are:

1. Atomic size 2. Electronegativity. 3. Metallic and non- metallic.

• Atomic size:

- Atomic radius is a measured for the atomic size and is measured by bicometre that is equal

to metre.

- Decreases in the period and increases in the group.

• Electronegativity:

- The ability of the atom to attract the electrons of the covalent bond towards itself.

- Increases in the period and decreases in the group.

• Polar compounds:

- They are the compounds in which the difference in the Electro negativity between their

atoms is relatively high.

• Metals:

-They are the elements that have less than 4 electrons in the outer most energy level.

- Metallic character decreases within the period and increase in the group.

• Non metals:

- They are elements that have more than 4 electrons in the outer most energy level.

- Non metallic character increases within the period and decreases in the group.

• Metalloids:

They are elements that have the appearance of metals and properties of non metals.

� Chemical properties of metals:

1. Reactions with dil. Acids:

Mg + 2 HCl MgCl2 + H2 ( Active metal)

CU + 2 HCl no reaction (Inactive metal)

2. Reaction with oxygen:

2Mg + O2 2MgO (basic oxide)

MgO + H2O Mg(OH)2 (alkaline solution)

3. Reaction with water:

Depends on the chemical activity of metals

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• Chemical activity series:

Is the arrangement of metals descending according to their chemical activity.

� Chemical properties of non metals:

1. Reaction with acids:

C + 2HCl no reaction

2. Reaction with oxygen:

C + O2 CO2 (Acidic oxide)

CO2 + H2O H2CO3 (Acidic solution)

In period:

1. atomic size decrease

2. Electro negativity increases.

3. metallic character decreases.

4. non metallic character increases.

In group:

1. atomic size increases.

2. Electro negativity decreases.

3. metallic character increases.

4. non metallic character decreases.

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Lesson (2) : Graduation of properties of the elements in M.P.T

I- Complete the following :

1. By increasing the atomic number in each period , the atomic size ………..while the

electro negativity …………………

2. In water molecule ,………….atom attracts the electrons of the bond more than

……..…….atom as it has higher ………………

3. Each period starts with ……………..and ends with …………………

4. The number of electrons in a positive ion is …………… than that of its atom .

5.By increasing the atomic number with in a group , the metallic property ………while the

non-metallic property …………….

6. The measuring unit of atomic radius is …………….

7. The elements which have less than 4 electrons at the outer most energy level are called

…………………..

8. The element …………….has the highest electro negativity which equals ……………

9. By increasing the atomic number in each period , the …………increases while

....................decreases .

10.The relation ship between the ………….of an element and its non – metallic property is

………………….

11. The strongest metallic element is …………while the strongest non-metallic element is

…………..

II- Write the scientific term :

1. The ability of the atom to attract the electron , towards itself in the covalent compounds .

[ ]

2.The atom of a metallic element that loses one electron or more during the chemical

reactions [ ]

3. The arrangement of elements in descending order according to their chemical

activity . [ ]

4. A gas that is produced due to the reaction between sodium and water.

[ ]

5. Covalent compound, the electro negativity between its elements is relatively

high . [ ]

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Show by a symbolic balanced equations :

1. Dissolving the magnesium oxide in water .

…………………………………………………………………………………….

……………………………………………………………………………………

2. Adding dilute hydrochloric acid to a piece of magnesium .

…………………………………………………………………………………….

……………………………………………………………………………………

3. Dissolving carbon dioxide in water .

…………………………………………………………………………………….

……………………………………………………………………………………

IV- What is the meant by :

1. Metals :…………………………………………………………………..

2. Metalloids : ……………………………………………………………..

3. Negative ion :……………………………………………………………..

V- Give reason for :

1. The atomic radius (size) decreases by increasing the atomic number within a

period .

…………………………………………………………………………………………………

……………………………………………………………………..

2. Hydrogen sulphide is not a polar molecule .

…………………………………………………………………………………………………

……………………………………………………………………….

3. Sodium has the ability to substitute hydrogen of acids .

…………………………………………………………………………………….

…………………………………………………………………………………….

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VI) Which graph represents relation between :

1) atomic size and period : ……………………………………….

2) Electro negatively and period : ………………………………..

property property property property

(a) (b) (c) (d)

Atomic

number

Atomic

number Atomic

number

Atomic

number

٩

Lesson (3) : Main groups in the modern periodic table

There are three main groups in the modern periodic table:

1. Group 1A (Alkali metals)

2. Group 2A (Alkaline earth metals)

3. Group 7A (Halogens)

� Alkali metals 1A:

- They react with water forming alkaline solutions.

2Na + 2H2O 2NaOH + H2

� General properties:

1. Good conductor of heat and electricity.

2. They have low density.

3. They are monovalent.

4. They are very active.

5. Their chemical activity increases within the group.

� Alkaline earth's metals:

1. They are the second group.

2. They are good conductor of heat and electricity.

3. Their densities are higher than that of the alkali metals.

4. They are divalent.

5. They lose electrons.

6. Their chemical activity increases within the group.

7. Their chemical activity less than that of alkali metals.

� Halogens:

1. They are elements of group 17.

2. They are monovalent.

3. They tend to gain electron.

4. They are diatomic.

5. They have graduated physical states.( solid – liquid – gaseous)

6. They are very active elements.

7. They react with metals forming salts( called halogens)

2K + Br2 2KBr

2Na+ Cl2 2NaCl

Each element replaces the element below it. Cl2+ 2kBr 2KCl + Br2

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Sodium:

It is used in cooling nuclear reactors.

Cobalt 60:

It is used in food preservation because it emits gamma rays which prevent the reproduction

of microbial cell.

Silicon:

It is used in making electronic devices as they are semiconductor.

Liquefied nitrogen:

It is used in preservation of cornea of eyes it has very low boiling

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Lesson ( 3) : Main Group in the Modern periodic table

I- Write the scientific term

1. The most active metal . [ ]

2. A gas that is used in cornea preservation . [ ]

3. Non- metal elements are not exist in nature in elementary state .[ ]

4. The element which has the largest atomic size . [ ]

5- Group of elements react with water forming alkaline solution [ ]

II- Complete the following

1. …………….is used to transfer the energy from inside the reactor to outside

2. The chemical activity of alkali metal ………….as the …………..increases

3. ………….emits ………….rays which prevent the reproduction of microbial cells .

4. As the atomic number increases in group “ 1 A” , the atomic size ………., the metallic

property ………….which the electro negativity ……………

5. Lithium element ……….in water as its density ……….than that of water .

6. Alkaline earth metals react with water to produce …………gas .

7. Metal oxides are called ………..while non – metals oxides are called …………..

8. …………..is used in the manufacture of electronic slides .

9. Valency of group 2 A is ……………….while group 7 A is …….……….

III) Give reason for :

1. Rubidium and cesium elements sink in water

…………………………………………………………………………………….

……………………………………………………………………………………

2. Elements of group ( 1 ) are known as alkali metals

…………………………………………………………………………………….

……………………………………………………………………………………

3. Elements of the same group has the same chemical properties .

…………………………………………………………………………………….

……………………………………………………………………………………

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4. Sodium is kept under the kerosene surface .

…………………………………………………………………………………….

……………………………………………………………………………………

5. Group 7 A elements are called Halogens .

…………………………………………………………………………………….

……………………………………………………………………………………...

IV) What are the importances of :

1. Silicon : ………………………………………………………………………….

……………………………………………………………………………………

2. Sodium : …………………………………………………………………………

……………………………………………………………………………………

3. Liquefied Nitrogen : ……………………………………………………………..

……………………………………………………………………………………

4. Cobalt 60 : ……………………………………………………………………….

……………………………………………………………………………………

V) What happens by adding :

1. Bromine to sodium chloride ……………………………………………

2. potassium to bromine …………………………………………………..

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Lesson 4 : Water

� Importance of water:

1. No living organism can live without water.

2. Water used as mean source f transportation.

3. Waterfalls used in generation of electricity.

� Sources of water:

1. Water areas (oceans, seas,…) 2.Rains. 3.Wells. 4. Springs.

� Structure of water:

1. Water formed of one oxygen atom and two hydrogen atoms.

2. Atoms are bonded with single covalent bonds.

3. The bond angle in water is 104.5 .

4. Water molecules are bonded together by hydrogen bonds.

� Physical properties of water:

1. Water can exist in the three physical states.

2. Water is a good polar solvent.

3. Pure water boils at 100 and freezes at 0 .

4. Water density decreases on freezing.

5. Water has high latent heat.

6. Water has high specific heat.

� Chemical properties:

1. Weakness of ionization.

(Ionization is the process of converting the molecules of some compounds into ions.)

2. Water has neutral effect on litmus paper.

3. Resistance of water to decomposition.

Water decomposes by electricity only ( electrolysis by Hoffman’s voltmeter )

2H2O 2H2 + O2

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� Water pollution:

It is the addition of any substance to water that causes gradual change in the properties of

water and affecting health and life of living creature.

� Water pollutants:

1. Natural pollutants:

Caused by natural phenomena.

-Volcanic eruptions.

-Death of living organisms.

-lightning through thunder storms.

2. Artificial water pollutants:

a. Biological pollution ( mixing wastes of living organisms with water).

b. Chemical pollution ( discharging of chemical wastes and sewage in water).

c. Thermal pollution ( increasing the temperature of water by cooling nuclear reactors)

d. Radiant pollution ( Dumping nuclear wastes in water)

� Protection of water:

1. Preventing getting rid of sewage in water canals.

2. Developing water treatment stations.

3. Disinfection of water tanks that are used to store water.

4. Don’t store tape water in plastic bottles (leads to cancer).

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Lesson ( 4 ) : Water

I-Complete

1. water molecules consist of …………………

2. The density of water in …………state is lower than its density in ………..state

3. The hydrogen bond is ……………………….

4. …………..…..and ……..…….…….are from covalent compounds .

5. ……………….is the bond between hydrogen atom and oxygen atom in water molecule .

6.Water has ……………boiling point .

7. …………….is the positive pole of Hoffman’s voltmeter .

8. Water has ……………effect on litmus solution .

9. Mixing of animals and human wastes with water leading to the infection by many diseases

such as ………………………and ………………….

10. ……………..is a kind of water pollution results from mixing of humans and animals

wastes with water .

11. …………..and ……………….are from water pollutants .

12. water is considered as a good ………….solvent .

II) Write the scientific term :

1. Ions responsible for the basic property in water molecules .[ ]

2. A kind of water pollution which results from discharging of factories residues .

[ ]

3. The angle between the two covalent bonds in water . [ ]

4. The bond which links the molecules of water . [ ]

5. They help in the pollution of water [ ]

III) Give reason for :

1. Ice floats on water surface .

…………………………………………………………………………………….

……………………………………………………………………………………

2. Adding drops of dilute acid to water during its electrolysis .

…………………………………………………………………………………….

……………………………………………………………………………………

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3. Water is important liquid in distinguishing of fires .

…………………………………………………………………………………….

……………………………………………………………………………………

4. Water is more polar than ammonia

…………………………………………………………………………………….

……………………………………………………………………………………

5. The high boiling point of water

…………………………………………………………………………………….

……………………………………………………………………………………

6. oxygen gas evolves above the anode during water electrolysis

…………………………………………………………………………………….

……………………………………………………………………………………

IV) What’s meant by :

1. Hydrogen bond : ………………………………………………………….………………

2. Water pollution : ………………………………………………………………………….

3.Ionization process : ………………………………………………………………………..

4. Pollutants : ………………………………………………………………………………..

V) From the opposite figure , answer the following questions :-

1. What is the name of this apparatus? …………………

2. Label the numbers (1) , (2) , (3) , (4) and (5) .

3. What happens if a glowing splint is put above

the anode and the cathode ?

…………………………………………………

………………………………………………....

4. Calculate the volume of the gas that evolves at

the anode if the volume of the gas that evolves at the

cathode is 20 cm3. ………………………………

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Unit (2)

Lesson (1) : The atmospheric layers

� Atmospheric envelope of Earth:

- It is a gaseous envelope that rotates around earth around itself and extends for 1000Km

� Atmospheric pressure:

- It is the weight of air column of the atmospheric height on a unit area.

- Measured by unit called bar or millibar.

- Measured by a device called barometer (aneroid used to determine weather conditions,

Altimeter used to determine the height of a plane)

� Normal atmospheric pressure:

- It is the atmospheric pressure at sea level and it equals to 101305mb.

� Isobar:

- It is curved lines that join the points of equal pressure in the atmospheric pressure maps.

� Layers of atmospheric envelope:

P.O.C troposphere stratosphere Mesosphere Thermosphere

Thickness 13 kilometer 37 kilometer 35 kilometer 590 kilometer

Temperature

Of the layer

-60 at the top Increases from

-60 to 0 at the

top

-90 at the top 1200 at its top

Atmospheric

pressure

100mb at its top 1mb at its top 0.01mb at its top

It contains

75%of the

Atmospheric mass

99% of water vapour

Most of ozone

Gas which is

Found in the

Atmospheric

Envelope.

Limited

Quantities of

Helium and

Hydrogen gases

Only.

Charged ions

In its upper

Pars.

Air

movement

vertically horizontally

١٨

� Van Allen belt:

They re two magnetic belts that surrounding the ionosphere and play an important rule in

scattering of the harmful charged cosmic radiations.

� Aurora phenomenon:

It is a phenomenon that appears as brightly colored light curtains seen from the both poles (the

North and South poles) of the Earth.

� Exosphere:

It is a region in which the atmospheric envelope is inserted with outer space.

١٩

Unit ( 2 )

Lesson ( 1 ) : Layers of atmosphere

I- Complete

1. Atmospheric pressure is ……………………………………………….

2. The measuring unit of the atmospheric pressure is …………….……..

3. The normal atmospheric pressure at sea level equals …………………

4. As the height increases the pressure ……………………

5. ………….is used to determine the elevation of planes depending on …………

6. ………………is a devise used to measure the atmospheric pressure.

7. …………. , ………….., …………… & …………..are the layers of the atmospheric

envelope .

8. The characteristics of the troposphere are :

1……………. 2………………….

3…………….. 4…………………

9. Calculate the height if the temperature at the sea level is 30 C & 7 C on the top of the

mountain .

10. From the properties of the stratosphere are

1……………. 2………………….

3…………….. 4………………… 5…………………

11. ……………layer is found at the end of stratosphere layer .

12. What are the characteristics of mesosphere

1……………. 2………………….

3…………….. 4…………………

13.What are the characteristics of thermosphere ?

1……………. 2………………….

3……………..

14. Van Allen Belts are ……………………………………………………………….……..

…………………………………………………………………………………………..……

15. Aurora phenomenon is …………………………………………………………..………

………………………………………………………………………………………………..

٢٠

II) Write the scientific term :

1. The layer of the atmospheric that contains 75% of the atmosphere mass

[ ]

2. The colored bright curtains at the poles . [ ]

3. The layer of the atmosphere which contains ions [ ]

4. A devise used to estimate the weather directly [ ]

5. the weight of the air column at the unit area [ ]

6. The layer of the atmosphere which the satellites float .[ ]

7. The layer which is preferred by pilots [ ]

8. The layer which the meteors burn in [ ]

III) Give reason for

1. As the height increases the pressure decreases

…………………………………………………………………………..

2. Van Allen Belts are very important

…………………………………………………………………………..

3. The occurrence of Aurora phenomenon

…………………………………………………………………………..

4. A weather phenomenon occur in the troposphere layer .

…………………………………………………………………………..

5. Mesosphere is much vacuumed layer

…………………………………………………………………………..

6. Meteors are burning in the mesosphere layer

…………………………………………………………………………..

7. Troposphere layer organizes the earth’s temperature

…………………………………………………………………………..

8. The temperature of the stratosphere increases gradually unit it reaches 0c

…………………………………………………………………………..

9. Ionosphere is called this name

…………………………………………………………………………..

10. Thermosphere is called this name

…………………………………………………………………………..

٢١

height height height

IV) Which of these represents the relation between air pressure & the height

Pressure Pressure Pressure

V) Calculate the temperature at the top troposphere layer if the temperature at

sea level is 24.5 Cº .

…………………………………………………………………………………………………

…………………………………………………………………………………………………

…………………………………………………………………………………………………

٢٢

Lesson (2) : Erosion of ozone layer and global warming

� Erosion of ozone layer:

- Ozone layer lies between 20:40 km above sea level.

- It absorbs ultraviolet radiations emitted from the sun.

- It is formed of 3 oxygen gases

O2 O + O

O + O2 O3

- Thickness of ozone layer measured by a unit called Dobson

- Natural amount of ozone equals 300 Dobson

� Harms of ultraviolet radiations.

Living

organism

Harmful effect

Human: - increasing the rate of skin cancer

- Cataract( a disease infects eyes)

- Weakness of the immunity system.

Amphibians - spoils eggs.

- decreasing rate of reproduction.

Marine

organisms

- Death of planktons which are main source of food for small

marine creatures.

- Destroying marine food chains.

Terrestrial

plants

- upset of the photosynthesis process.

- Shortage of crops production.

� Pollutants of ozone layer:

1. Chlorofluorocarbon compounds.

2. Methyl bromide.

3. Halons.

4. Nitrogen oxides.

� Protection of ozone:

- In Montreal protocol many recommendations were signed

٢٣

� Global warming:

It is continuous increase in the average temperature of the Earth's near- surface air.

� The most important greenhouse gases:

1. Carbon dioxide.

2. Chlorofluorocarbon.

3. Methane.

4. Nitrous oxide.

5. Water vapour.

� Greenhouse effect:

It is the trapping of infrared radiation in the troposphere layer due to the increase in green

house gases.

٢٤

Unit (2)

Lesson (2) :Ozone layer

I- Complete

1. Ozone layer is found in ………..layer at height of ………..to …………km

2. Ozone layer is formed of …………by the effect of …………..rays

3. According to Dobson the ozone layer thickness at S.T.P = ………….so it = ……………

4. Dobson unit are divided into …………..,………….&……………

5. The …………U.V rays are very harmful

6. Ozone erosion is caused by :

1…………….. 2…………….. 3…………….

4………………

7. CFCL3 ……….. + ……………

B + O3 C + D

D + O3 ………. + B

8. Global warming is ………………………..

9. The most dangerous compound that harms the Ozone layer is …………..

10. Green house effect occurred by ………… , …………., ………… & ………… gases .

II) Give reason for :

1. The occurrence of the global warming phenomenon

…………………………………………………………………………..

2. The occurrence of the ozone hole

…………………………………………………………………………..

3. Ozone layer is very important

…………………………………………………………………………..

4. Using CFC must be reduced

…………………………………………………………………………..

5. Co2 gas concentration increases the temp. of the earth .

…………………………………………………………………………..

6. Melting the ice of poles due to the green house effect

…………………………………………………………………………..

7. The occurrence of drought waves

…………………………………………………………………………..

٢٥

III) Write the scientific term :

1. The phenomenon that causes the drought waves , flood & tropical hurricane .

[ ]

2. The measuring unit of ozone layer . [ ]

3. The increase of Co gas concentration [ ]

4. The rays which affect the ozone layer [ ]

5. It’s used as pesticides to preserve stored crops . [ ]

6. It’s used in fire extinguishers & affects the ozone layer

[ ]

7. The gas which produced as a result of burning fuel of U.S.A planes .

[ ]

8. The U.V. rays which cause the great harmful to the earth’s surface .

[ ]

٢٦

Unit (3)

Lesson (1): Fossils

� Fossils: They are traces and remains of old living organisms that were preserved in the

sedimentary rock.

� Trace: Traces of old living organism indicates its activity during its life.

� Remains: Parts indicate the remains of old living organism after death.

� Types of fossils:

1. Complete body fossil. ( mammoth& Amber)

2. Cast.

3. Mold.

4. Petrified fossils.

� Importances of fossils:

1. Age determination of sedimentary rocks.

2. Figuring out the paleoenvironment.

3. Studying life evolution.

4. Petroleum exploration.

� Index fossil:

They are fossils of organisms that have lived for short periods of time in the past and had a

wide geographic distribution then became extinct.

� Fossil record:

They are fossils that exist in the rocks of different areas that indicate the extinction and

evolution of organisms.

٢٧

Unit (3)

Lesson (1) : Fossil

I) Write the scientific term :

1. Remains of old organisms that lived in the past for a certain period and the

became extinct . [ ]

2. Replacing part by part , the wood material of trees by silica to form petrified

wood . [ ]

II) Complete the following :

1. Archaeopteryx represents the link between ………………..and …………….

2. Fossils are used in ……………… exploration and defer mining the age of ……………

III ) Compare between :

1. Mold and cast .

2. Remains and trace .

IV) State the different types of fossils .

٢٨

Lesson (2) : Extinction

� Extinction:

- It is the continuous decrease without compensation in the number of a certain species of

living organisms until all members die out.

- It is the dying out of all members of species of living organisms.

� The moment of extinction:

It is the date of death of the last member (individual) of that species.

Factors affecting the extinction:

Factors of the old extinction:

1. Meteorites that impacted earth.

2. The onset of the long glacial age.

3. Emission of poisoning gases from volcanoes.

Causes of recent extinction:

1. Destroying the natural habitat.

2. Over hunting.

3. Environmental pollution.

4. Climatic changes and natural disasters.

� Examples of the old extinct animals:

1. Dinosaurs.

2. Mammoth

� Examples of recent extinct animals:

1. Dodo bird.

2. Quagga.

3. Passenger pigeon.

4. Australian wild cat ( Tasmanian cat)

5. Golden frog.

٢٩

� Examples of endangered animals:

1. Panda bear.

2. Rhinoceros.

3. Bald eagle.

4. Ibis bird.

5. Papyrus plant.

� Food chain:

It is the path of energy that transmits from living organism to another in the ecosystem.

� Simple ecosystem:

It is the ecosystem that contains a few no. of species of living organisms and affected by the

absence of one type of living organism. (desert ecosystem)

� Complicated ecosystem:

It is the ecosystem that has multiple members and not affected by much by absence of a

species of living organism. ( ocean ecosystem)

� Natural protectorate:

They are safe areas established to protect endangered species in their home land.

� The most important protectorates:

1. Blue stone in USA. ( grey bear)

2. Panda protectorate in China (panda bear)

3. Ras Mohamed in Egypt (coral reefs and fish).

٣٠

Lesson (2) : Extinction

I) Write the scientific term .

1. The death of all members of species of living organism . [……..….………..……]

2. Extinct animal has a wolf’s head , dog’s tail and a tiger’s skin […………………….....]

3. Endangered animal that affected by building of high dam . […………………..…...]

II) Write down factors affecting Extinction .

…………………………………………………………………………………………………

…………………………………………………………………………………………………

III) Remove odd word and write down the common factors of the rest .

1. Dodo / Quagga / Bald Eagle / Tasmanian cat .

2. Panda / Rhinoceros / Golden Frog / Bald Eagle .

IV) Mention the characteristics of each :

A) Rod Mohamed protectorate …………………………………………………..……………

…………………………………………………………………………………………………

B) Wadi Hetan area . ……………………………………………………..…………..………

…………………………………………………………………………………………………

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Model exam (1)

Question (1):-

A) Write the scientific term :

1. The ability of the atom to attract the electrons of the chemical bond towards itself .

[ ……………..……..…..]

2. Safe areas established to protect endangered species in their home land .

[…………….………….]

3. The process of converting the molecules of some covalent compounds into ions .

[………………....….….]

4. It is the continuous decrease without compensation in the number of a certain species

until all members die . [………………....….….] B) What is the importance of :

1- Cobalt 60 .

2- Ozone layer .

C- Locate the position of the following elements in the modern periodic table :-

13 Al , 2 He , 19 K

Question (2) :-

A) Complete the following statements :

1- ………………… and ………….…… are from the recent factors that cause extinction

of some living organisms .

2- ……………… and ……….…. are from the most important gases that harm the earth .

3- ………………………….…… are remains of the old living organisms that preserved in

sedimentary rocks .

4- Water has a high boiling point due to the presence of …………………..……… bond

between its molecules .

B) Compare between the following :

1) Group (1) and group (2) [ according to : Name – Valence ]

2) Stratosphere and Mesosphere [ according to : Temperature – type of gases ]

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Question (3):-

A) Choose the correct answer :

1.The elements that have both properties of metals and non-metals are …………..

a- inert gases b- halogens c- metalloids d- actinides

2. ………………… is a bird that disappeared from a swam due to loss of its nests .

a- Bald eagle b- Ibis bird c- Passenger pigeon d- Golden frog

3. Elements of block “d” are called …………………………..

a- lanthanides b- noble gases c- transition elements d- actinides

4. A replica of the outer shell shape of the skeleton of a living organism is ……………

a- mold b- trace c- petrified wood d- cast

B) Problem :

Calculate the height of a mountain if the temperature at its fool is 20 c° and at it top

is – 6 c°

C) Complete the equations :

1) CFCl3 violet

ultra …………. + ……………..

2) Na + …………. Na OH + …………..

Question (4) :-

A) Put ( √√√√ ) or ( × ) and correct the wrong ones :

1. Amphibian was the first vertebrate that appeared . [ ]

2. Copper and Carbon don’t react with hydrochloric aid . [ ]

3. Mendeleev arranged the elements ascendingly according to atomic number .

[ ]

4. Drainage of factories wastes in rivers and seas is a biological pollution .

[ ]

B) Give reason for :

1. Ionosphere is important for radio stations .

2. Over hunting of “ The Tasmanian cat” .

3. Within a period , the atomic size decreases by increasing the atomic number.

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Model exam (2)

Questions: st

1

-A) Choose the correct answer:

1- Mammoth is a type of elephants that extinct by ………………

a- winds b- silica c- snow d- amber

2- In the same period, the element which has the highest electronegativity lies in group

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

a- 1A b- 2A c- 5A d- 7A

3- …………...……… has the wolf’s head , dog’s tail and skin like a tiger.

a- Passenger pigeon b- Tasmanian cat c- Golden frog d- Dinosaur

4- If the temperature at the sea level is 29 Cº , the temperature at the top of a mountain of

height 4 km will be ……………… Cº

a- 5 b- 3 c- zero d- 55

5- Moseley classified the elements in ascending order according to their ……………..

a- atomic no. b- atomic weight. c- sublevels d- all the previuos.

B) Complete the following equations:-

1- CF Cl3 → VU . ………….. + ……………..

2- Cl2 + 2k Br ………….. + ………….

-C) Give reason for:

1) Methyl bromide is a harmful compound.

2) Adding drops of dilute acid to water during its electrolysis by Hoffman’s voltameter.

3) Dodo bird was an easy target for hunters.

Questions: nd

2

-A) Put ( √ ) or ( × ):

1- Non-metal oxides dissolve in water forming acids. ( )

2- Pilots prefer to fly their planes in troposphere layer. ( )

3- Environmental pollution is one of the recent reasons of extinction. ( )

4- The bond between water molecules is “single covalent bond”. ( )

5- Replacing the wood materials of trees by silica is called petrification. ( )

6- Cesium is considered as the least active metal in the alkali metals group. ( )

B) Locate the position of the elements in the modern periodic table:-

1- 13Al 2- 20Ca

C) Compare between:-

1) Group ( 2 ) and group ( 17 ) [ according to: Name – Valency ]

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3rd

Question:

A) Write the scientific term:-

1- A gas that is used in preservation of the cornea of the eye. [ ………..………. ]

2- Two magnetic belts surround the ionosphere and reflect the harmful cosmic radiation.

[……………………]

3- It is the process of converting the molecules of some covalent compounds into ions.

[ …………………. ]

4- Traces and remains of old living organisms that are preserved at sedimentary rocks.

[ …………………. ]

5- A group of elements that found in the middle of the periodic table and includes ten

vertical columns. [ …………………. ]

-B) What is the importance:

1- Altimeter 2- Natural protectorate

-C) Give one example for:

1- A green house gas. 2- Metalloid.

3- Endangered animal.

Questions : th

4

-A) Complete the following statements:

1- From the water pollution …………….. and ……………

2- ………….. is the coldest atmospheric layer while ………….. is the area where satellites

float around the Earth.

3- If an element ( X ) in the modern periodic table lies at period 2 group zero, its atomic

number equals ……………..

4- Ozone molecule is formed by combining one ………………. atom with an oxygen

molecule by the effect of …………….. radiation.

5- …………. is a continuous decrease in the number of a certain species of living organisms

without compensation.

6- By increasing the atomic number in each group, the …………..….. increases while

…………. decreases.

B) What happens if:-

1- There is no ozone layer.

2- Sodium is not kept under the surface of water.

-C) Correct the underlined words:

t used to measure the is a part from million million parts of a meter tha Dobson -1

atomic radius.

t reacts with chlorine gas bottles because i glassp water in We haven’t to keep the ta -2

to cause cancer.

aurora phenomenon.Melting of ice in polar areas is one of the negative effects of the -3

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Model exam (3) Question [ 1 ]

A) Put ( √ ) or ( × ) :

1- The density of group (2A) elements is less than that of group ( 1A) elements . ( )

2- Water can dissolves all ionic and covalent compounds . ( )

3- The measuring unit of atomic radius is “ Millimeter ” . ( )

4- The group zero contains the inert gases . ( )

5- Within a period , by increasing the atomic number the electronegativity decreases .

( )

6- H2O , NH3 and H2S are polar compounds . ( )

B) What is the importance of :

1- Liquified nitrogen . 2- Silicon slides .

C) Locate the position of the following elements in the modern periodic table :

1- 20Ca 2- 10Ne

Question [ 2 ]

A) Complete the following statements :

1) ……………. are the elements that start to appear in the fourth period .

2) The bond between the oxygen atom and the hydrogen atoms in the water molecule is

……………………. bond .

3) ……………….. is the most active metal while ……………. has the highest

electronegativity value .

4) Lanthanides and actinides are located in ……………. block .

5) The metals tend to ……………… electrons forming …………….. ions .

6) The scientist ……………….. corrected the atomic weight of some elements which were

estimated wrongly .

B) Which of the following graphs :

property property property property

atomic no. atomic no. atomic no. atomic no.

(a) (b) (c) (d)

1- Represents the graduation of atomic size in group (2A) .

2- Represents the graduation of mentality in each period .

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Question [ 3 ]

A) Write the scientific term :

1- The process of converting the molecules of some covalent compounds into ions .

[………………………..]

2- A table in which the elements are arranged ascendingly according to their atomic numbers

and the way of filling the energy sublevels . […………………………]

3- The elements of group (1A) in the modern periodic table . […………………………]

4- The descending arrangement of elements according to their chemical activity .

[…………………………]

B) Give reason for :

1- Water has a high boiling point .

2- Halogens are called “ salt forming ”.

C) Hafman’s voltameter :

1- What is the name of this apparatus ?

2- Lable the numbers (1) , (2) , (3) and (4) .

3- If the volume of the evolved gas number (1) is

8 cm3 , calculate the volume of the evolved

gas number (2) .

Question [ 4 ]

A) Choose the correct answer :

1- When the atmospheric temperature increases , the temperature of the human body doesn’t

change due to high …………………….. of water .

a) specific heat b) latent heat c) boiling point d) freezing point

2- The atomic number of the element that follows (14

7 N ) in the same group is ………………

a) 8 b) 17 c) 15 d) 17

3- The density of water in the solid state is ………………. its density in the liquid state .

a) equals b) less than c) more than d) a or b

4- The chemical properties of magnesium (12Mg) are similar to ………………………….. .

a) 11Na b) 19K c) 3Li d) 20Ca

5- All the following are from metalloids except …………….. .

a) tellurium b) silicon c) bromine d) boron

B) What happens when :

1- Drinking water has high concentration of mercury and arsenic .

2- Dissolving magnesium oxide in water . ( An equation can be used )

C) Complete the following equations :

1) S + O2 ……………………….

2) Cl2 + 2 K Br …………..... + ………………..

Acidified water

1 2

3 4