First term
Prepared by :Heba mahmoud Egyptain poineer language school
Unit (1) Lesson (1) Matter:
Matter and its construction Matter and its characteristics
It is anything has mass and occupies a space (volume). We can differentiate between some objects by some physical properties such as color, taste or smell. Ex: Silver & Gold Sugar
& salt
Vinegar & perfume
by color. by taste. by smell.
N.B: 1. Smell and taste senses are not used to distinguish between harmful objects especially in the laboratory. 2. Color, taste and smell can’t be used to differentiate between other substances as oxygen and water because both of them are colorless, tasteless and odorless. 3. There are other characteristics used to distinguish between some substances Such as: Density: Substances
Float on water
Sink in water
Ex: wood – oil – cork
Ex: iron nail a piece of
(have lower density than
candle
water)
(have higher density than water)
A-Density:
M
It is the mass of unit volume (1cm3)
Density =
Mass (m) gm Volume (v) cm3
D
V
gm/cm3
What is meant by the density of water is 1 gm / cm3 This means that the mass of 1cm3 of water = 1gm. GR: Equal masses of different substances have different volumes and vice versa? Because they are different in densities. Problem: In an experiment for determining the density of a liquid the following results were recorded. Mass of empty beaker = 75gm Volume of liquid = 100 cm3 Mass of the beaker with the liquid = 135gm. Find the density of the liquid. Solution: Mass of liquid = 135 – 75 = 60gm. D = m/v =
60
/100 = 0.6 gm / cm3 .
GR: Water is not used to put out (extinguish) petrol (oil) fires.
Balloons full of hydrogen or helium rises up in air carrying flags during festivals.
Applications on density: a) Archimedes had discovered the purity of a crown made of gold mixed with copper by determining the mass and the volume of the crown then he calculate its density and compare it with the known density of gold he found it is different. b) Determination of the quality of powdered milk: Ex: Give that the density of the natural milk is 1.03 gm / cm3 . How to detect the quality of powdered milk? B-Melting (fusion) and boiling points: Matter has three states Solid state
melting
liquid state
boiling
Gaseous state.
Melting point: It is the temperature at which the substance changes form solid state to liquid state. Some solids have low melting points as wax, butter and ice. Some solids have high melting points as iron, copper and aluminum.
Boiling point : It is the temperature at which the substance changes from liquid state to gaseous state Applications on melting process
Alloy
Manufacture of cooking pans
Copper – gold alloy
Nickle – chrome alloy
(used for decoration)
(used in making heating coils)
C- Hardness: Solid substances Soft at room temp
Need heat to become soft and
Don’t melt by
Ex: rubber
reshaped
heating
Ex: iron , copper , …. (metals)
Ex: coal.
4) Electrical conductivity: Substances Conductors
Insulators
Allow electricity to flow through.
Don’t allow electricity to flow through
Ex: 1) Metals(iron , copper
Ex: 1) Wood, plastic, sulphur and
aluminium , ...
phosphorus.
2) Acidic and alkaline solutions.
2) sugary solution and solution of
3) Some salt solutions.
hydrogen chloride in benzene.
5) Thermal conductivity: Substances Conductors
Insulators
Allow electricity to flow
Don’t allow electricity to flow through
through.
Ex:
Ex: 1) Metals(iron , copper , ...)
1) Wood, plastic.
Give reasons:
1. Electric wires (cables) are made of copper or aluminum.
2. Cooking pans are made of aluminum.
3. Handles of cooking pans are made of wood or plastic.
4. Screw drivers are made of steel, while their handles are made of wood or plastic.
Metals and chemical activity Very active metals
Less active metals
Inactive metals
They react with
They react with
They don’t react with
atmospheric oxygen
atmospheric oxygen
atmospheric oxygen due
when they are exposed
after a long time and
to their weak chemical
to humid air and lose
rust after a long time
activity, so they used in
their metallic luster
Ex: iron – copper –
jewellery industry.
Ex: sodium - potassium
aluminum
Ex: silver – platinum – gold
N.B: Poor active (inactive) elements (silver , gold , chrome , nickel , .)are used to cover objects made of iron to protect them from rust and corrosion. G.R: 1. Steel bridges and the holders of light bulbs are painted from time to time.
2. Metallic spare parts of care are covered with grease.
3. Washing of cooking pans made of aluminum with a rough object.
Lesson (2)
Matter and energy
The interconversion of matter from one state to another by heating (gains energy) or by cooling (loses energy). Gaining energy
Melting
Evaporation
Freezing
Condensation
Losing energy Water cycle in nature is a good example for the interconversion of the state of matter. The physical change: It is the change in the state and the shape of the substance. The chemical change: It is the change in the structure of the substance. Mass and physical state of the substance The mass of the substance remains constant either it is: a) Divided into small parts
(small pieces).
Ex: dividing an orange into b) Changed from one state to another Ex: melting of wax.
Mass and chemical change of a substance: Activity: 1. Get a candle and record its mass. 2. Get a small quantity of soda lime and record its mass. 3. Light the candle and put it in a tube then cover the tube with heating grid and put soda lime above it. 4. Put off the candle after a sufficient time then record its mass again. 5. Determine the mass of soda lime again. Obs: The mass of the candle decreases, while the mass of soda lime increases. The increase in the mass of soda lime is higher than the decrease in the mass of the candle. Explanation: The candle is composed of carbon and hydrogen (hydrocarbon substance) on burning it combines with atmospheric oxygen gas giving co2 gas and water vapor which are absorbed by soda lime. Conclusion: The change of the mass of the substance is due to the change in its components(structure) Law of conservation of matter: Matter neither created nor destroyed from nullity (nothing) but it can be changed from one state to another.
G.R: The increase in the soda lime mass is greater than decrease in the candle mass.
Energy: It is the ability to do work or cause change. Units of energy: 1) Calorie
2) Joule
1 Calorie = 4.18 Joule. Forms of energy: 1) Heat energy
2) Mechanical energy
3) Tide energy
4) Magnetic energy
5) Solar energy
6) sound energy
7) Chemical energy
8) Wind energy
9) Electrical energy
Some examples for the interconversion of energy from one form to another: Electric heater
1-Electrical energy
Heat energy. Electric lamp
2- Electrical energy
Light energy. Magnetic needle
3- Electrical energy
Magnetic energy. Solar cell
4-Solar energy (light)
Electric energy. Dry cell (battery)
5-Chemical energy
Electric energy.
Law of conservation of energy “Energy neither created nor destroyed but it can be changed from one form to another”. Matter and energy In 1905,”Max Plank” put a theory which states that: “It is possible to change the matter into energy and vice versa” Energy = converted mass (kg) x constant 2 Einstein deduced value the value of this constant which = (Light speed)
Light speed = 3 x 108 m/sec. Energy (Joule) = converted mass (kg) x (3 x 108)2 Problem: m/sec. Calculate the energy in joules emitted when 1000 kg is decreased to 999 kg of a certain substance. Solution: Energy = converted mass x (3 x 108)2 = (1000 – 999) x (3 x 108)2 = 9 x1016 Joules. In 1925, the Egyptian scientist “Dr. Ali Mustafa Musharafa” said that: “Matter, energy and radiation are various forms for one thing” This means “when a certain mass of matter disappears, it is changed into one form to energy”
Lesson (3) Matter construction Matter consists of molecules and molecule consists of atoms. The molecule: It is the smallest part of matter which can exist in a free state and keep the properties of matter.  The properties of the molecule of matter: 1-They are in continuous motion in all directions. Ex: A drop of potassium permanganate or ink in a beaker containing water. 2-There are intermolecular spaces among the molecules of matter. Ex: Adding 300 cm3 of water to 200 cm3 of alcohol than the resulted mixture will be less than 500cm3 3-There are attraction forces among the molecule of water. Give reasons: 1-A drop of ink spreads through water. Bec. : The molecules of ink are in continuous motion in all directions between water molecules. 2-The volume of a mixture of water and alcohol is less than the sum of their volumes before mixing. Because some molecules of alcohol occupy the intermolecular spaces between water molecules.
Compare between P.O.C Solid state The least motion Motion of molecules (Oscillatory) Intermolecular Narrow spaces Intermolecular Very strong forces Definite Shape (fixed) Definite Volume
Liquid state
Gaseous state
Limited
The most motion (Relatively free)
Medium
Very large
Medium
Weak
Indefinite
Indefinite
Definite
Indefinite
ďƒ˝ The change of matter from the solid state to the liquid state: Melting: It is the change of matter from the solid state to the liquid state by heating Explanation: When a solid substance is heated: the velocity of its molecules increases and some of them overcome the intermolecular forces, so the intermolecular spaces increase leading to the change of matter from the solid to the liquid state G.R: Heat changes matter from the solid state to the liquid state ďƒ˝ The change of matter from the liquid state to the gaseous state: Vaporization: It is the change of matter from the liquid state to gaseous the state by heating Explanation: When a liquid substance is heated to its boiling point: the velocity of its molecules increases and some of them overcome the intermolecular forces, and the intermolecular spaces increase so, they escape in the form of vapor.
G.R: 1-Heat changes matter from the liquid state to the gaseous state
2-Gases have indefinite volumes and shapes Because their molecules are relatively free due to their large intermolecular spaces and very weak intermolecular forces. ďƒ˝ Matter and molecules: The molecules of the same matter are similar in their properties but the molecules of different matters are different. The molecule is composed of tiny particles called atoms G.R: The molecules of different substances are different in their properties Because they differ in their structure Atom: It is the fundamental building unit of matter
Kinds of molecules Element
Compound It is formed from combination of 2 or more different elements with The smallest pure form of matter that can't be constant weight ratio analyzed chemically into simpler form Ex: Its molecules are formed of similar atoms Water (H2O) Table salt (NaCl) Its molecules and atoms are different from *3 atoms "Sodium chloride" those of another element *2 elements *2 atoms *2 hydrogen atoms *2 elements and 1 oxygen atom *1 sodium atom and Elements are divided into: 1 chlorine atom
Mixture
Ammonia (NH3) *4 atoms *2 elements *1 nitrogen atom and 3 hydrogen atoms
Solis elements Liquid elements Gaseous elements They are composed of one atom Monoatomic Diatomic Monoatomic Diatomic Triatomic Ex: (1 atom) (2 similar atoms) (1 atom) (2 similar atoms) (3 similar atoms) Iron (Fe) Ex: Ex: Ex: Ex: Ex: Sulphur (S) Mercury (Hg) Bromine (Br2) Inert gases Hydrogen (H2) Ozone (O3) Magnesium (Mg) Helium (He) Nitrogen (N2) Note: Aluminium (Al) Neon (Ne) Oxygen (O2) One drop of water is composed of Carbon (C) Argon (Ar) Chlorine (Cl2) millions of water molecules which Copper (Cu) Krypton (Kr) Fluorine (F2) can't be seen by naked eye or Xenon (Xe) microscope Radon (Rn)
Lesson: 4 Atomic structure of matter Atom : It is the smallest particle of an element that can make chemical reaction OR: It is the basic (fundamental) building unit of matter It cannot exist in free state
Symbols of some elements 1- The symbol consists of one or two letters from the Latin name. 2- The first letter must be capital but the second letter must be small.  Examples Hydrogen H Aluminium Al Helium He Sulphur S Carbon C Chlorine Cl Nitrogen N Potassium K Oxygen O Calcium Ca Neon Ne Iron Fe Sodium Na Copper Cu Magnesium Mg Argon Ar Lithium Li Silicon Si Mercury Hg Zinc Zn Silver Ag Lead Pb Gold Au Phosophorous P Flourine F Bromine Br Iodine I
The atomic Structure The atom
Central nucleus 1- Positive charge (+ve).
Electrons 1- Negative charge (-ve). 2- Mass of electrons is very small if it is compared to the mass of nucleus.
2- Mass of the atom is concentrated in the nucleus.
3- The electrons revolve around the nucleus in elliptical orbits called energy levels.
3- The nucleus consists of two particles :a) Proton:(+ve) positive charge. b) Neutrons: (Âąve) neutral charge. G.R 1- Atom is electrically neutral. Bec. Number of positive protons = number of negative electrons . 2- Nucleus is electrically charged. Bec. It contains positive protons . 3- Mass of atom is concentrated in its nucleus. Bec. Mass of electrons is neglected if it is compared to the mass of nucleus. * Atomic mass : (mass number) It is the sum of number of protons and neutrons in the nucleus of the atom. Atomic mass = no . of protons + no . of neutrons
* Atomic number It is the number of protons in the nucleus or the number of electrons around the nucleus in the normal state. Note. - Atomic mass is written above the symbol.
Atomic mass
- Atomic number is written under the symbol. Atomic number Example 23 Na 11 Atomic no .
= ……………………………
no. of protons = …………………………… no. of electrons = …………………………… Mass no. = …………………………… Atomic mass = ……………………………. no. of protons + no. of nutrons = ………………….. no. of neutrons = …………………………………… Note. no. of neutrons = Atomic mass – Atomic no.
What is meant by: 1-The atomic number of aluminium = 13 ……………………………………………………………………………… 2-The mass no. of aluminium = 27 ………………………………………………………………………………
Energy Levels K
L
M
N
O
P
Q
+
Lowest energy
highest Energy They are orbits around the nucleus at which electrons move . They are 7 energy levels (K,L,M,N,O,P,Q). The energy levels have an elliptical (oval) shape. The 7 energy levels have different energies . The lowest energy level is (K) and tThe highest energy level is (Q). Electronic configuration Notes: 1- Electrons revolve around the nucleus in an energy levels. 2- Each energy level has a maximun number of electrons. 3- The max. no. of electrons in each energy level can be calculated by the formula. X = 2n2 Where
X is the max. number of electrons. N is the number of the energy level. 2 X = 2 n is the relation between the eneergy level and the maxmium number of electrons in it . Q what is the max. no. of electrons in the first energy level (k)? K X = 2n2 N=1 X = ?? 2 + 2 X = 2 (1) X = 2(1) X = 2 electrons. So :- The first energy level (K) is saturated by two electrons.
What is the max. no. of electrons in the second energy level (L) ? K L X = 2n2 N=2 X = ?? 2 8 + X = 2 (2)2 X = 2(4) X = 8 electrons. So:-The second energy level (L) is completed by eight electrons. What is the max. No. of electrons in the third energy level (M) ? K L M X = 2n2 n=4 X = ?? 2 8 18 + X = 2 (4)2 X = 2(9) X = 18 electrons So:-The fourth energy level (M) is completed by eighteen electrons. What is the max. No. of electrons in the third energy level (N) ? K L M N X = 2n2 n=4 X = ?? 2 8 18 32 + X = 2 (4)2 X = 2(16) X = 32 electrons So:-The fourth energy level (N) is saturated by 32 electrons.
Give reason The formula X = 2n2 cannot be applied to the energy level higher than four . Bec. the atom becomes unstable if the energy level contains more than 32 electrons. So:- The first energy level (K) contains 2 electrons. - The second energy level (L) contains 8 electrons. - The third energy level (M) contains 18 electrons. - The tourth energy level (N) contains 32electrons. Note: The outer most energy level for any atom can't take more than 8 electrons except "K" level which can't take more than 2 electrons. The electron doesn't leave its energy level under the normal conditions. If the atom gains amount of energy equal to the difference between the energies of the 2 levels it can move to the higher one and the atom called an excited atom Excited atom: It is the atom that gains a quantum of energy.
Quantum energy: It is the amount of energy lost or gained by the electron when it transfers from one energy level to another If an electron gains a quantum of energy it moves to the higher energy level If an electron losses a quantum of energy energy it moves to the lower energy level
Draw the electronic configuration of the following: 1
H no. of electrons =1 1 +1
+1 ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ 4
He no. of electrons =2 2 +2
+2
ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ 7
no. of electrons =3
) Li ( 2, 1 3 +3
12
no. of electrons =6
) C ( 2, 4 6 +6
14
no. of electrons =7
) N ( 2, 5 7 +7 16
no. of electrons =8
) O ( 2, 6 8 +8
ــــــــــــــــــــــــــــــــــ ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ 23
no. of electrons =11
) Na ( 2, 8, 1 11
+11
ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ 35
no. of electrons =17
) Cl ( 2, 8,6 17 +17
32
no. of electrons =16
) S ( 2, 8,6 16 +16
36
no. of electrons =18
) Ar ( 2, 8,8 18 +18 39
K ( 2, 8, 9 ) the no. of electrons in the outer energy level 19
must not more than (8) 39
K ( 2,8,8,1)
no. of electrons =19
19 +19
ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ 40
K ( 2, 8,8,2 )
no. of electrons =20
20 +20
Give reason
The electrons in the outer energy level must not more than 8 electrons. Bec. The atom will be unstable if outer energy level contains more than 8 electrons. Active elements Inactive elements Elements in which the outer most Elements in which the outer most energy level contains less than 8 energy level completely filled with 8 electrons electrons (except helium contains 2 electrons in its outer most energy level) They participate in a chemical They don't participate in a chemical reaction with other atoms to reach reaction as they are stable the stable state Ex: Ex: inert gases Sodium , chlorine,oxygen,……… (helium –neon-argon-krypton-xeononradon)
G.R: 1-Hydrogen (1H) is an active element while Neon (10Ne) is in active one
2-Noble gases molecules are monoatomic.
3-Hydrogen can participate in a chemical reaction while neon is not.
Unit 2
Energy
Lesson 1
Energy, resources and forms
Food is burned inside the body cells producing energy needed for the body activities. Energy: It is the ability to do work or to make a change. Work: When a force acts on a body at rest and it moves a distance in the force direction (displacement) this means a work is done. Work = Force × displacement W = F . d N/m or Joule Joule Newton meter Problem: Calculate the work done by a fireman to lift a force of 65 Newton's a distance of 10 meters long. Solution: W = F × d = 65 × 10 = 650 Joule Forms of energy: 1- Mechanical energy (potential energy + kinetic energy). Ex: Energy stored in stretched spring 2- Electric energy (Ex: electric generator). 3- Sound energy (Produced from T.V, radio). 4- Light energy (Electric lamp – Kerosene lamp). 5- Chemical energy (Food – Car batteries). 6- Heat energy (Heater – Burning food). 7- Nuclear energy.
Some resources of energy: 1- Sun (The permanent source of energy) 2- Wind (Renewable source of energy) 3- Waterfalls (Renewable source of energy) 4- Food (Through chemical reactions) 5- Fuel (Through chemical reactions – non renewable source of energy) 6- Nuclear reactions (Produce electric and heat energies) G.R: Some countries use sun, wind energy and movement of water in generating electricity? Bec. They are cheap and clean sources of energy. The mechanical energy: * It is the total sum of both potential and kinetic energies of the body. * Each body has a constant value of mechanical energy. Ex: waterfall * At the top of the water fall: P.E = max K.E Zero * At the mid height: P.E = K.E * At the bottom of the water falls: K.E = max P.E Zero N.B: *When the object is at the highest point its energy is only potential energy * When it reaches the ground the energy is only kinetic energy. * At the mid distance between the highest point and the ground P.E = K.E * Work done = Mechanical energy = Potential energy + Kinetic energy
Potential energy : It is the stored energy in the object due to a work done on it. Factors affecting the potential energy: 1- Weight of the object 2- The height of the object from the ground Potential energy (Joule) = Weight (Newton's) × Height (Meter) N.B: Weight = mass × Acceleration of gravity = m x g * The potential energy of an object is directly proportional to the height and the mass of the body. Problem: An object weights 25 N and it is at height of 4 meters calculate the potential energy if its height decreased by 1 m.
Kinetic energy: It is the energy of the moving body or the work done during the motion of an object. Factors affecting the potential energy: 1- Mass of the object. 2- The velocity (speed) of the object. K.E = 1 2mass(velocity )2 Kg
m/s2
K . E1 2 M V 2 N.B: The kinetic energy of a moving body is directly proportional to its mass and the square of its velocity.
Problem: 1- A racing bike is moving with velocity of 20 m/s. Calculate its kinetic energy by knowing that the mass of the bike is 7 kg?
2- A stone was thrown up and when it reaches 5 m its velocity was 4 m/s. Calculate the P.E, K.E and the work done if you know that the stone weight and mass are 4 N and 0.4 Kg respectively.
3- A person threw a ball of mass 0.5 kg upwards vertically at a certain point at a height 4 m from the ground, its velocity was 4 m/s. Find the work done on the ball (Acceleration due to gravity = 10 N/Kg)
Q: Compare between potential energy and kinetic energy. P.O.C
Definition
Factors affecting it
Law used
Example
Potential energy
Kinetic energy
Lesson 2
Energy transformations
Activity: To prove law of conversation of mechanical energy: • From the figure as shown. • Observation: - The vibrating body moves on both sides around its original position (B) - The velocity of the vibrating body decreases as it goes away from its original position . - The velocity of the vibrating body is maximum when it passes its original position during its movement .
A
B
• Explanation: - You did work to pull the ball; the ball gained it in the form of potential energy. - When the ball is left, the potential energy changes gradually into kinetic energy - When the ball passes its original position (B) its velocity maximum So, its kinetic energy is maximum and its potential energy is zero. - When the ball reaches the maximum height (A & C) its velocity is zero So its potential energy is maximum and its kinetic energy is zero. • Law of conservation of mechanical energy: The sum of potential energy and kinetic energies of an object under the effect of gravity is a constant value.
C
Problem: A moving pendulum has P.E 0.8 joules at the maximum displacement If the mass of a ball is 0.16 kg and acceleration due to gravity is 10 m/s2 find:a) The height of the pendulum ball at the maximum displacement. b) The kinetic energy of the ball at maximum displacement.
Activity: To make a model for the simple electric cell. • Tools: A large lemon, compass, copper wire and zinc rod. • Steps: 1- Press the lemon to increase its juice. 2- Dip the zinc rod and a wire terminal into the lemon. 3- Call the wire around the compass and tie the other wire terminal in zinc rod. • Observation: - The compass deflects indicating that an electric current flows through the circuit. • Explanation: - When two different metals are dipped in acidic solution (lemon) chemical energy changes into electric energy. • Conclusion: - The simple cell consists of an acidic solution dipped in two different metals . In simple electric cell: chemical energy Electric energy
Activity: - You are given the following tools how can you make alarm for a deaf friend and another alarm for a blind friend? (Electric lamp – electric bell – battery – switch – connecting wire) - Alarm system for a deaf friend - Alarm system for a blind friend
Changes in energy:Application
From
To
Simple electric cell
Chemical energy
Electrical energy
Electric lamp
Electric energy
Heat and light energy
Car engine
Chemical energy (fuel)
Heat energy then chemical energy
Car dynamo
Kinetic energy
Electric energy
Car lamp
Electric energy
Light energy
Car radio cassette
Electric energy
Sound energy
Electric heater of car air conditioner
Electric energy
Heat energy
Sewing machine Washing machine
Electric energy
Mechanical (Kinetic) energy
Torch
Chemical energy (battery)
Light energy
Television
Electric energy
Sound and light energy
Alarm clock
Chemical energy (battery)
Kinetic energy and Sound energy
Mobile phone
Electromagnetic energy
Sound energy
Energy and environment: There are a lot of damages due to some of the technological applications of energy: Example
Its danger
1- Car exhaust
Causes pollution of air which causes chest and eye diseases
2- Military explosions
They causes war and death
3- Chemical pesticides
Cause pollution of plants so cause cancer
4- Nuclear weapons
5- Mobile phones
Cause the massive destruction and leave harmful effects behind them for a long time Newtons have harmful effects on people suffering from heart diseases (electromagnetic pollution)
Technology has a negative effect when man use it in : 1- Killing and war 2- Massive destruction
Lesson 3 Heat energy • Heat is a form of energy. • Heat transferred from an object of higher temperature to another of lower temperature. (hot cold) • Heat transfer stops when the temperature of them becomes equal. Sources of heat: 1- The sun is the main source of heat on the Earth’s surface. 2- Friction change kinetic energy to heat energy. Movement of particles and temperature: • The temperature increase by increasing the movement of the balls. Explanation: When you shake the cup the velocity of the ball increases causing increase in kinetic energy and temperature. Due to the increase in friction between them producing heat energy. The temperature: • It is the condition which states the direction of heat energy whether from the object or to it when it comes in contact with another. • Temperature
K.E
• Temperature is measured by thermometer
The transfer of heat: Convection Conduction (in liquids and gases by (in solids) Heat is transferred from movement of molecules) the hoot end of solid body to the cold one
Through liquids
Radiation (in gases and space) It doesn’t need medium to transfer through
Through gasses
When the liquid is heated its molecules move away from each other so the liquid expands and its density decrease and become lighter so it rises up to replace the cold liquid Give reasons: 1- The air conditioner is fixed at the upper part of the room.
2- The freezer of the fridge is found at the top of the fridge.
3- The electric heater is placed at bottom of the room .
4- The heat of the sun is not transferred by conduction or convection.
Heat in our life: There are many technological applications depend on heat and operated by: 1- The solar energy. (Permanent source of energy) 2- The petroleum fuel. (Non- renewable source of energy) 3- The electricity. (Renewable source of energy) Examples: The device
The source of energy
The kind of energy source
Electric heater
Electricity
Renewable
Solar heater
Sun
Permanent
Electric stove
Electricity
Renewable
Gas stove Gas oven
Natural gas ( Butan gas)
Non- renewable
The sun: • It is the main source of energy on earth. • The energy of the sun called solar energy. • It is the cleanest source of energy because it doesn’t cause pollution. Importance of solar energy: 1- Plants use solar energy during photosynthesis and change it into chemical energy stored in food. 2- The solar energy responsible for evaporation of water. 3- The solar energy is the reason for the wind movement to generate electricity.
Importance of solar energy: 1- Production of electricity. 2- Providing satellites and space ships. 3- Operating solar heaters. 4- Desalination of sea water to get fresh water. Give reasons: The production of electricity from solar energy is preferred than that produced burning of fuel.
Unit 3 Diversity and Adaptation in Living Organisms Lesson: 1 Living organism's diversity and principles of their classification Diversity of living organisms a) Diversity of animals: Animals differ in:
Size Big Ex: Elephant Rhincoceros
Living place Small Ex: rabbit, rat and lizard
in water Crocodile Fishes Hippopotami
on earth Horse Lion Dog
b) Diversity of plants: Huge trees small
Small herbs
Plants with large sized leaves
Camphor Palm trees
Clover Banana plant Gargeer (water cress)
Plants with sized leaves Molukhia plant
c) Diversity of micro-organisms: They are living organisms that can't be seen by naked eye but they can be seen under microscope They are unicellular organisms (have one cell) such as: 1-Amoeba 2-Paramecieum 3-Euglena
Classification of the living organisms: First: Classifying plants: According to the Shape
Ways of reproduction
Some plants can’t be distinguished into roots, stems and leaves such as the green, Red and brown algae.
Most plants have roots, stems and leaves such as corn, wheat, palms and camphor plants.
Spores
Seeds
Ex: Voughair and Adiantum Gymnosperms
Angiosperms (Flowering plants)
Seeds of are formed inside cones not inside pericarp Ex: Pine plants and Cycas Monocotyledon plants Ex: Maize and wheat plants.
Dicotyledon plants Ex: Beans and pea plants.
Third: Classifying of animals according to the nature of body supporting Soft body The body doesn't have a support Ex: Jelly fish- octopus worms External support Snails-crustacea (shrimps)-mussels
Supported body
Internal support Vertebrates as: Birds, cows and fish
Fourth: Classifying arthropods according to the number of legs: Arthropods are invertebrate animals that characterized by a type of legs known as jointed legs. Arthropods can be classified according to the number of these legs
1.Insects 2.Arachnids have 3 pairs of have 4 pairs of jointed legs jointed legs Ex: locusts, bees, Ex: spider and scorpion flies, and cockroaches.
3. Myriapods have large numbers of jointed legs . Ex: scolopendra and Julius.
Fifth: Classifying mammals according to the type and number of teeth. A. Edentates (Teeth less mammals) Ex: the sloth and armadillo. Animals have front teeth extending outwards to capture the insects. Ex: hedgehog
B. Mammals having teeth
Animals have pointed canines and molars with sharp projections Ex: lion and tiger.
Animals have sharp incisors
Rodents Have one pair of incisors in each jaw Ex: rat and squirrel
Lagomorphs have two pairs of incisors in the upper jaw and one pair in the lower jaw Ex: rabbit.
Taxonomy It is a branch of biology searching the similarities and differences among living organisms, and placing the similar ones in groups according to a certain system in order to ease their studying.
«Species» the basic classification unit for living organisms Linnaeus had considered the species as fundamentals of a natural classifying system.
Species Is a group of more similar living organisms shape that can reproduce to give birth of new fertile individuals that are able to reproduce and therefore keeping the existence of the species. Although cats differ from each other they differ more than rabbits and dogs so it is impossible for cats to mate (reproduce) with rabbits. Production of fertile offspring can take place among any pair of cats although they differ in shape and size. N.B: The intercourse between horse and donkey produces mule sterile The intercourse between zebra and donkey produces zonkey female
Lesson: 2 Adaptation and diversity of living organisms
Adaptation Is a modification in a living organism or its body structure or even the biological function of its organs to become more adapted to the environmental conditions where it lives in.
Types of adaptation A. Structural adaptation (anatomical): It studies the structure of one body organ such as the horse hoof and camel pad structure. The camel pad ends in a thick flat • one to enable the camel wondering through the hot desert sands where as The horse hoof ends in a strong solid end to help the horse go through the rocky soil. B. Functional adaptation: The ability of some organs and tissues to do a specific function Ex: 1-secreting sweat in case of high temperature as in human 2-secreting poison as in snakes.
C. Behavioral adaptation: It takes place in activity of some animals at certain time of day or the year Ex: Bird's migration or some animals are active in different times of the day light such as the active birds during the day and night.
Reasons of adaptation: 1- Getting food. 2- Escaping from enemies. 3- For plants, most plants are adapted to the different environmental conditions. 4- Way of movement.
First: Adaptation and motion The animal Whales and dolphins
Bats
Horse Monkeys and gorilla
Modification in its limbs The 2 fore limbs are modified to become Paddles (fin-like structure) Wings The 2 fore limbs are modified to become wing-like structure Its limbs are modified to end with strong hoof The bones of fore limbs and fingers are elongated
The aim of modification for swimming
for flying
for running on a rocky soil Climbing the trees and catching things
Second: Adaptation and nature of food
1. In birds: The bird Predatory birds Ex: hawks and vultures
Birds feed on shallow water worms and snails (Heron-hoopoe)
The water birds Ex: ducks and geese
Modification of its beak and legs Beaks: Have sharp and strong crooked beaks to enable to tear the prey. Legs: have four fingers end in strong and sharp claws three front (anterior) fingers and a back one (posterior). To hunt their preys. Beaks: Have long and thin beaks to pick up worms and snails Legs: Have long and thin legs ending in thin fingers to walk in water. Beaks: Have wide indented flatted beaks in the two sides to filter the food from water Legs: palm to help swimming
All the previous adaptations are structural adaptation
Adaptation in Insectivorous plants: Predacious plants are self - feeding green plants that can perform photosynthesis and make carbohydrates such as any other plants. These types of plants can't absorb the nitrogenous substances needed to form proteins so some parts are modified in order to pounce and digest the insects then absorb the nitrogenous substances that their bodies need. Ex: Drosena, dieonea and halophila.
Lesson: 3 Adaptation and continuity of life Some living organisms couldn’t adapt to the environmental changes, so they perished (extinct) as what happened to dinosaurs and mammoth. Many other species of living organisms had succeeded in continuation of life due to their adaptation with the environmental changes.
Examples of adaptation in living organisms:
1. Hibernation. 2. Aestivation. 3. Birds migration. 4. Adaptation in the aquatic and desert plants. 5. Adaptation for hiding 1. Hibernation: In winter, when temperature is decreased, a)some animals hide in burrows such as some reptiles and some insects b) some animals bury themselves in mud, stop feeding and their activities are decreased, as frogs, to overcome the decreasing of temperature. In spring, when the environment conditions improve, these animals return back to their normal activities.
2. Aestivation: In summer, when temperature rises up, especially in desert areas, living organisms face an extreme rising in temperature and a shortage in water and rains. These organisms become dormant and hide in humid burrows in order not to be affected by rising of temperature. Examples Jerboa, desert snail and some other insects.
3. Birds migration: (behavioral adaptation) Some species of birds are adapted to the environmental conditions by migration from cold and polar regions, during winter, to more lighted and warmer regions for reproduction Then, they return back to their original habitats in favor to the climatic conditions in spring. These birds inherit this behavior where they migrate into the same places at the same times every year. Example: quail bird.
4. Adaptation in the aquatic and desert plants: Aquatic and desert plants face contrasting conditions. Aquatic plants live : a. submerged totally in water as elodea plant. b. partially such as hyacinth plant (Nile rose). These plants are exposed - especially the totally submerged ones- to 1- A shortage in water dissolved oxygen and light. 2- The presence of water currents. Desert plants, on other hand, face a shortage in water and an extreme rising in temperature during daylight. A. Adaptation of aquatic submerged plants: Example: Elodea plant. • Roots are weak because they are not needed for water. •Leaves are ribbon like small sized, so they will not be cut by water currents. They are sessile (neck less), so their connection with the stem will be stronger. stem is elastic, so it will not be torn by water currents. It contains many • air chambers in its inside to store a part of oxygen gas produced in photosynthesis process to be used in respiration and to help plant float in the more lighted regions of water. B. Desert plants: • Roots: are well formed. They may extend a) Vertically in the soil for great depths to reach the humid layers of soil, such as calamagrostis plant. b) Horizontally to absorb a largest amount of rain water or dew and store it in the stems, as in opuntia plant, or in the succulent (juicy) leaves and as in cactus plant.
• Leaves: are small sized, may be ribbon like and spiraled and stomata are little in number and lie deeply to reduce the loss of water by transpiration, as in calamagrostis plant, or are used in storing water, as in cactus, and surrounded with a waxy layer to prevent water loss by transpiration. • Stems: are short to avoid the strong winds, as in cactus plant. They may be rich in chloroplasts to perform photosynthesis, and they are reduced into spines, as in opuntia plant.
( P.O.C )
Roots
Leaves
aquatic submerged plants
Desert plants
Weak
Well formed
because they are not needed for water.
They may extend: 1- Vertically in the soil such as calamagrostis. 2- spread horizontally: such as opuntia.
Ribbon and small sized
Small sized may be: a. ribbon b. spiraled as calamagrostis
To avoid cutting (torn) by water currents.
(and stomata are little in number and lie deeply)
c. Surrounded with a waxy layer. as in cactus plant Elastic
Stems
To avoid cutting (torn) by water currents.
Contains air chambers -To store oxygen. - makes the plant floats.
Short to avoid the strong winds They may be rich in chloroplasts to perform photosynthesis Reduced into spines as in opuntia plant.
Examples
Elodea plant
Calamagrostis opuntia plant cactus plant
5. Adaptation for hiding: Some animals can colour themselves with the dominant colours in the environment, so they become no prominent aim for their enemies, as: 1- The leaf - insect which is hardly discovered by its enemies because it looks like the plant leaves exactly in color and shape of wings. 2- The stick - insect which looks like the branches of plants as well. 3- Chameleon colours itself with the dominant colours of the environment to be hidden from its preys of insects to capture them and feed on.
Camouflage: Is the ability of some living organisms to be hidden from their enemies or to capture the preys in the predator species.
Camel is the desert ship
Camel is considered as one of the most adapted animals to live in deserts. It is also considered as an example for the structural, functional, and behavioral adaptations that helped it live in the hard conditions of desert.
Some adaptation features in camel: • Camel has a plentiful number of lachrymal glands and two rows of long eyelashes that protect its eyes from the dispersing sand on time of sandstorms. Camel can also control the opening and closing of its nostrils.
• The ear is small and covered with dense hair from inside to obstruct dust and sand. • The thickness of fur Differs at different body regions. It is more dense over the vital body regions to provide protection to them from the extreme cold at night. It is also little dense over other body regions to ease heat loss by radiation during daylight. •The legs end in a broad pad to prevent their diving in the smooth sand, and thick skin to protect them from high temperature of the soil. •The forked upper lip mouth and the strong enamel of its teeth enable it to eat the spiny and dry desert plants without harming it. • Camel stores an amount of fats in its hump to keep its survival for 3 - 4 months without eating any food. • Camels blood temperature is not constant as in other
mammals It changes from 34ºC in the morning to 41ºC during the daylight hours, so it has no need for sweating. • Camels sweat glands don’t start sweating unless the blood temperature reaches 40ºC. • Drinking water: Camel can drink 100 liters of water through 10 minutes only without affecting its blood composition. After that, camel can survive for a week or more without drinking any additional amounts of water. • Camel can lose 25% of its body weight when water and food are not available and its blood composition remains constant. This rate exceeds the other mammals ability by twice nearly.
Name:-…………………
Subject: - Science
Date:-……………………
Electrical and thermal conductivity 1-Electrical conductivity: Substances Conductors
Insulators
Allow electricity to flow
Don’t allow electricity to flow
through.
through
Ex: 1) Metals(iron , copper
Ex: 1) Wood, plastic, sulphur and
aluminium , ...
phosphorus.
2) salt solutions.
2) sugary solution
5) Thermal conductivity: Substances Conductors
Insulators
Allow electricity to flow
Don’t allow electricity to flow
through.
through
Ex: 1) Metals(iron , copper )
Ex: 1) Wood, plastic,glass ,rubber and air.
1-Give reasons: 1. Electric wires (cables) are made of copper or aluminum.
2. Cooking pans are made of aluminum.
3. Handles of cooking pans are made of wood or plastic.
4. Screw drivers are made of steel, while their handles are made of wood or plastic. 2-Compare between electric conductors and insulators.