grade 10 science exam review-2

8/12/2019 Grade 10 Science Exam Review-2

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Grade 10 Science Exam ReviewCell Parts and Functions

Organelles

o Structures that carry out specific functions within the cell.

Cell membrane

o Usually acts as a wall, holding the contents of the cell together and controlling what

goes in and out of the cell (food and waste).

Cytoplasm

o The liquid between the cell membrane and the nuclear membrane. Holds the

organelles, enzymes, amino acids, ATP and carbohydrates.

Mitochondria

o Sausage shaped organelles that release energy so the cell can function, the

mitochondria is also called the powerhouse of the cell.

Nucleus

o The large round structure in the center of the cell, the Nucleus controls the center of thecell and directs all of the cells activities, also contains the genetic material DNA

(deoxyribonucleic acid).

Nuclear membrane

o Holds the contents of the nucleus together, also controls what goes in and out of the

nucleus.

DNA (deoxyribonucleic acid)

o Holds/ carries the genetic code, contains all of the instructions for running the cell

Nucleolus

o The dark area inside of the nucleus that makes ribosome parts (looks like a wad of gum

in Ms. Lees diagram)

Ribosomeso the sites where proteins are assembled

Endoplasmic reticulum (ER)

o A series of small tubes that carry materials through the cell. The rough ER houses some

of the ribosomes for making trans membrane proteins. The smooth ER is responsible for

makingfats and oils.

Golgi apparatus

o Receives, modifies and transports proteins made at the rough endoplasmic reticulum,

creates vesicles and lysosomes

Vesicles

o Small, membrane bound sacs used to transport materials throughout the cell

Lysosomes

o Saclike structures that allow digestion. Lysosomes can be used to break down damaged

organelles or used by white blood cells to destroy invading bacteria

Cell wall

o Found in plant cells, not animal cells, tough and rigid (made of cellulose- a glucose

polymer)

Vacuole

o Found mainly in plant cells, used for storage offood and water, they give support to the

cells structure


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Cilia

o Short, normally numerous, hair like extensions that beat in a coordinated fashion. Ex:

paramecium is covered with cilia that help it swim through the water.

Flagellum

o Long whip like tails that help the cell move. Human sperm cells are able to move due to

their flagellum.

Plant Cell/Animal Cell

Plant Cell

Note: Golgi vesicles, amyloplasts, vacuole membrane, raphide crystal and

druse crystal were not in any handouts or discussed in class


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Animal Cell

The Cell Cycle and Mitosis

Cell cycle

o The life of a cell including cell growth, DNA replication, preparation for mitosis and

mitosis; normal cells live from 50-60 cycles

Mitosis

o The phase of the cell cycle in which the cell divides into two identical daughter cells, the

stages of mitosis are interphase, prophase, metaphase, anaphase and telophase. (to

remember: IPee on the MAT)

Chromatin

o A combination of DNA and proteins

Chromosomes

o made of condensed DNA, formed during mitosis

Sister Chromatids

o Identical copies of a chromosome joined by a centromere

Interphase

o During interphase the cell grows, but can only grow to a certain size. Beyond that the

surface area of the cell is too small for the volume of the cell and it is not possible for

the cell to get enough nutrients and waste in and out of the cell quickly.

Prophase

o During prophase the chromatin condenses into chromosomes, which are sister

chromatids at this point. The mitotic spindles, which will pull the chromatids into

position, form. In animal cells the centrioles move to opposite ends of the cell to formthe poles of the mitotic spindles, in this stage the nuclear structure and membranes will

also break apart.

Metaphase

o During metaphase, chromatids line up at the cells equatus (AKA: the equatorial plate)

and the mitotic spindle fibres attach themselves to the centriole. The fibres link each

sister chromatid to opposite poles.

Anaphase


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o During anaphase the sister chromatids are pulled apart by the spindle fibres. The

separated chromosomes move to opposite ends of the cell.

Telophase

o In telophase cytokinesis occurs, which is the splitting of the cells cytoplasm. In animal

cells, a cleavage furrow forms, which is a pinching in the middle of the cell to form two

new cells. In plant cells a new cell wall is formed between the two new cells.

First growth phase

o The cell produces new proteins and organelles

Synthesis phase

o The DNA is replicated in preparation for mitosis

Second growth phase

o The cell produces the organelles and structures needed for cell division

Cell necrosis

o The death of a cell through injury or disease; not preprogrammed

Apoptosis

o Programmed cell death which occurs when a cell is no longer needed. For example, the

body produces a lot of different cells when an infection like the flu is present, but after it

has fought off the infection, those cells are no longer needed and they die.Carcinogens

Substances that cause cancer through the mutation of the DNA. They generally fall in three

categories, however there is a fourth.

o Viruses (ex: human papilloma virus can cause cervical cancer)

o Radiation (ex: UV radiation from the sun can cause skin cancer)

o Hazardous materials (ex: asbestos can cause lung cancer)

o Genetics (ex: breast cancer genes)

Cancer

Cancer cells are cells that do not undergo apoptosis at the right time and divide out of control.o Cancer occurs when the DNA in the cell is damaged in some way so that the cells

instructions (like when to stop replicating) are changed

o Cancer cells rapidly divide, and produce more cells than are needed. These new cells can

begin to form a mass or a tumor. These cells are unspecialised cells (but do not aid in

the tissue function), and therefore crowd out other functioning masses, using up their

space, energy and resources to grow. Cancer becomes deadly when it spreads into

organs and tissues, preventing their proper functioning.

How does cancer spread

o It spreads in two ways:invasion and metastasis.Invasion is the migration into

neighboring tissues. (Physically growing into the neighbouring tissue.) Metastasis is the

movement of cancer cells through the bloodstream or lymphatic system to other sites in

the body. Benign tumors cannot spread by invasion or metastasis. Malignant tumors are

capable of spreading by invasion or metastasis, and are by definition cancer

How is cancer treated

o Although there is no cure for cancer there are 3 main treatments

o Chemotherapy

Chemotherapy destroys cells which are in mitosis.Since cancer cells replicate

more often than other cells, they are vulnerable. However, other rapidly


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dividing cells are also targeted, such as hair, skin and stomach lining.

(chemotherapy uses comes a drug)

o Radiation

Radiation is directed at tumors and mutates the DNA of the cells. Cancer cells

are more vulnerable than normal cells because they have less ability to repair

damaged DNA than healthy cancer cells. The damage of DNA can lead to the

death of the cell, or the slowing of its replication

o Surgery

Surgeons can remove tumors from the body, but must be careful not to damage

surrounding tissue. Also all cancer cells must be removed or the tumor will

return

What are the major functions of each type of tissue?

Be able to give an example of each type of tissue.

Epithelial tissue

o Animal tissue

o Line our body cavities and the outer surface of our bodies

o Protects and keeps our organs in placeo Forms glands

o Examples:

skin

Lining of lungs, gastrointestinal tract, urinary tract, cornea

Adrenal and sweat glands

Connective tissues

o Support and protect structures

o Forms blood, stores fat, fills empty space

o Examples:

Tendons and ligaments

Bones Cartilage

Blood

Muscle tissue

o Animal tissue

o Allows movement

o Examples:

Skeletal (voluntary, ex: arms and legs)

Smooth (involuntary, ex: blood vessels and stomach)

Cardiac (involuntary, heart muscles)

Nervous tissue

o Animal tissue

o Transmits and stores information

o Restores _____________

o Examples:

Brain and spinal cord

Peripheral nervous system

Organ systems

What organs are involved in each system and what are their basic functions?


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Integumentary system

o The skin, hair, sweat glands and nails

o Protects the body

o Helps the body control temperature

Digestive system

o Mouth, esophagus, stomach, pancreas, tongue, gallbladder, liver, intestines, rectumo absorbs nutrients from food and eliminates solid waste

Respiratory system

o Nose, Mouth, trachea, lungs, bronchi, alveoli, diaphragm

o Exchange of gasses

Circulatory system

o Heart, veins, blood, arteries

o Transports materials within the body

Imaging the human body

Be able to explain one type of body imaging in depth

Be able to describe each type of imaging and how it works X-ray

o Emits radiation into body, bones will glow white with radiation.

o Can be used for bones, cardiac and vascular systems

o Used in medicine to check for broken bones and in dentistry to observe non visible

parts of teeth

Fluoroscopy

o Provides video footage, X-ray transmitted through body and images received by

fluorescent plate on opposite side from X-ray

o Can be used for full body, but works better when focused on a specific part

o Diagnostic abilities, can also be used to monitor internal procedures

Ultrasoundo uses sound waves, conducts images of internal structure

o Generally used in soft tissues, major organs

o Used to diagnose heart problems and to view fetuses

Computed tomography

o Uses computer processed x-rays to produce topographic images of the human body

o Used for mainly soft tissues, blood vessels but mainly used for brains

o Diagnosing cancers

Magnetic resonance imaging (MRI)

o Emits a magnetic field that reacts with hydrogen atoms within your body to produce

images

o Soft tissues, brain, heart, livero Diagnosing

Nuclear medicine

o Used for entire body

o Detection and treatment of cancer

Positron emission technology (PET)

o Tracers are emitted into the body, these emit positrons and produce a 3d image of

your body


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o Generally soft tissues, can be used for whole body

o Diagnosing heart disease and brain disorders

Biophotonics

o uses light to make pictures of the inside of bodily structures with a tube that goes

into the body

o light and camera attached to the tubeo used for digestive tract, soft tissues, search for cancerous growths in stomach or

intestines, and sometimes the inside of eyes

Chemistry notesRecall

An ion is a charged atom formed by gaining or losing electrons

An ion is negative when it has a surplus of electrons and is positive when it has a lack of electrons

Full valence and stability

An atom that has a full valence shell is considered stable

All atoms want to be stable, like their nearest noble gas (in terms of valence configuration [how many

shells])

Noble gases are the most stable because of their full valence configuration, thus they do not try to mix

with other atoms

Examples

Sodium, which has 1e- on its outer shell, will lose that electron; because it is easier for the atom to do

such than it is to gain 7e- Sodium will form neon which has a total of 10e-

By losing an electron, sodium will become positive

Fluorine which has 7e- on its outer shell, will gain another electron, because it is easier for that atom to

gain 1e- than to lose 7e- Fluorine will form neon which has a total of 10e-

By gaining an electron, fluorine will become negative

Ionic bonding

When forming ions, the electrons always have to go to somewhere, or go to somewhere

Examples


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NaCl or table salt is an ionic compound comprised of sodium and chlorine

If you look at the makeup of sodium we will find that it has one electron on its outer shell, and if you

look at the makeup of chlorine you will see that it has seven electrons on its outer shell. In ionic

bonding, one atom must give its surplus electrons to the other atom, making one positive and the other

negative.

Ionic compounds are wrote as Metal-Non-metal-Ide

When writing the chemical formulas you must consider the ions of each atom, and determine if the

positive charge is equal to the negative charge.

If they are then you will write the formula with no subscripts, for example NaCl, the negative charge of

sodium is equal to the positive charge of chlorine.

However if the charges are not equal, you must determine how many of each is needed to make the

compound neutral.

Examples:

1.) In the case of calcium and fluoride, calcium will form the ion 2+, and fluorine will form the ion 1- The

charges of these two will not become neutral when bonded.

To do this you must have one calcium atom, and two fluorine atoms.

This will form the chemical formula of CaF2

2.) In the case of magnesium and oxygen, Mg will form an ion of 2+ and O will form an ion of 2-,

because the charge of these ions will be equal, only one of each is necessary to make the compoundneutral. The chemical formula will be MgO (not Mg2O2)

3.) In the case of aluminium and sulfur, Al will form the ion of 3+ and S will form an ion of 2-, because

the charges of these are not equal, two aluminium atoms and three sulphur ions will be needed to

make the charge of the compound neutral. The chemical formula of this will be Al2S3

Note: An interesting relationship that makes writing the compounds easier to write is to switch the

charges of the two atoms in the ionic compound. Al with its ion of 3+ and S with its ion of 2- are written

as Al2S3.

Mg and O both have an ion of 2+/-, but are not written as Mg2O2 however, because they are reduced to

their simplest form of MgO

Rules of writing chemical formulas

1.) The numbers telling how many of each atom is in the molecule are called subscript and are written

on the same line, below the atomic symbol.


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2.) The charges of atoms may not be written above, although you may do it as a step to figuring out the

formula

3.) The Charges (+,-) are not written in the formula

4.) Always reduce the subscripts to their lowest common factors

Naming ionic compounds

The metal cation is named first, and keeps its name, the non-metal is written next and it must have ide

added to its ending

Example:

NaCl, is written as Sodium-Chloride. Sodium, the metal is written first, and keeps its full name, while

chlorine, is written last an as chloride

Practice

MgO is written as Magnesium-Oxide Al2S3 is written as Aluminium-Sulfide

CaBr2 is written as Calcium-bromide NaP3 is written as Sodium-Phosphide

Transition metals

Some metals have more than one possible valence; these metals are under the acronym of CLINT

(Copper, Lead, Iron, Nickel, and Tin).

Copper can have possible valence of 1+ and 2+, (I, II)

Lead can have possible valence of 2+ and 4+ (II, IV)

Iron can have possible valence of 2+ and 3+ (II, III)

Nickel can have possible valence of 2+ and 3+ (II, III)

Tin can have possible valence of 2+ and 4+ (II, IV)

Writing chemical formulas

In the case of Iron (II) oxide, the chemical formula is still written metal, then non-metal

Then write the ionic charges above the symbols. The ionic charge for the multivalent element can be

found in the name Iron(II) oxide, Fe2+O1-

Using the previously mentioned trick, transfer the charge numbers between the two atoms within the

molecule, making Iron (II) oxide FeO2

Practice

Tin (IV) chloride would become SnCl4 Manganese (IV) oxide would become MnO4

Copper (II) phosphide would become CuP2 Iron (II) Fluoride would become FeFl2

Lead (IV) sulphide would become CuS4 Nickel (II) chloride would become NiCl2


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Writing the compound name

First, you must recognise that it has a transition (CLINT) metal, if it doesnt, then it is just written as

Metal, Non-metal, with no numerals.

If it is indeed a transition metal, then you must figure out which version of the metal we have.

To figure this out, you do a reverse-crossover, then check to see if the non-metal is the correct ion

Then write the formula with numerals in the middle Metal (numeral) Non-metal.

Example:

CuCl2, which is technically Cu1Cl2 when crossed over is Cu2Cl1, Cu2 is copper with the roman numeral

of II, which is written as Copper (II) Chloride

Try it

Name the compound

Check if the metal is a transition metal

Perform the reverse crossover

Check if the non-metal is the correct ion

If so, write as Metal (Numerals) Non-metals

If not, then multiply both the metal and the non-metal to make oxygen the correct ion

Try with

SnBr4___________________________ Tin (IV) Bromide

Fef3____________________________ Iron (III) Fluoride

CuI_____________________________ Copper (I) Iodide

CuS_____________________________ Copper (II) Sulphide

Sn3P2___________________________ Tin (II) Phosphide

FeC2____________________________ Iron (II) Carbide

Practice

Name the following compounds write the names for the following components

Magnesium oxide Li2O

Sodium fluoride AlCl2Aluminium nitride MgS

Potassium sulfide CaO

Lithium iodide KBr

Calcium bromide BeF


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PolyatomicThe Polyatomic is a group of atoms that tend to stay together and carry an overall ionic charge.

These charges are displayed in the table. (Note: you must memorize the name of the ion)

Name Formula Charge

Acetate CH3COO 1-

Ammonium NH4 1+

Bicarbonate HCO3 1-

Carbonate CO3 2-

Chlorate CLO3 1-

Hydroxide OH 1-

Nitrate NO3 1-

Nitrite NO2 1-

Phosphate PO4 3-Sulfite SO3 2-

Sulfate SO4 2-

Naming polyatomic compounds

The same as in writing the ionic compounds, the structure for the compound name begins with the

metal, and is followed by that of the polyatomic ion.

Example:

CaCO3 the first part of this formula, Ca is calcium, a metal, and the second is the polyatomic ion CO3 or

carbonate, so the polyatomic ions name is Calcium Carbonate.

Try it

MgSO4______________________________________________________________Magnesium-sulfate

Mg(NO3)2___________________________________________________________Magnesium-nitrate

Al2(SO4)3___________________________________________________________Aluminium-sulfate

(NH4)2O ____________________________________________________________Ammonium-oxide

NaOH_______________________________________________________________Sodium-hydroxide

Writing polyatomic compound formulas

The same as naming ions, write the metals symbol first, and follow with the polyatomic ion.

Example


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Beryllium sulfate Al(OH)3

Magnesium hydroxide CuSO4

Calcium sulfate NaOH

Lead (II) nitrate CuNO3

Copper (II) hydroxide FeSO4

Tin (IV) carbonate Pb(CO3)2Iron (II) sulfate Fe2(SO4)3

Lead (IV) nitrate Sn(NO3)2

Molecular compoundsDefinition

Covalent bonding is when electrons are shared within the bond

Molecular compounds contain covalent bonds and are composed of two non-metals. Their

characteristics are that they generally have low melting points, and they dont conduct electricity.

Lesson I

What happens when neither element is strong enough to pull an electron away from the other?

Example

In the case of two hydrogen atoms, neither is able to pull away from the other, therefore they combine

to make H2, sharing the two electrons among themselves.

Note

Electrons are always shared in pairs

Example II

In the case of Hydrogen and oxygen, oxygen needs two more electrons, and hydrogen only has one

electron. The one oxygen would bond with two of the hydrogen atoms, making H2O, also known as

water.

Writing formulas for molecular compounds with single bonds

First, write the symbols, starting with the symbol of the element closest to the left of the periodic table.Then write the combining capacity, which has the same value as the ionic charge, but without + or -.

Then crossover to produce the subscripts

Example

Carbon and Sulfur

CS

C(4)S(5) -note that the numbers in the brackets should be written above the symbols


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C5S4

Keep in mind that molecular compounds can have single double or triple bonds

Naming molecular compounds

The ending s of molecular compounds must end with -ide, also, the compound names begin with the

element to the left of the periodic table.

When naming the compounds, prefixes are used to specify the number of atoms present for each

molecule.

The prefixes

Mono-, which can be dropped if it is the fist element

Di-

Tri-

Tetra-

Penta-

Hexa-

Hepta-Octa-

Nona-

Deca-

Try these

NO____________________

N2O___________________

NO2___________________

N2O3__________________

N2O4__________________

N2O5__________________

C5S4___________________

SO2____________________

SF6____________________

CCl4___________________

NI3____________________

Diatomic molecules

Some elements commonly form compounds with two atoms, all of which are gasses, with the exception

of bromine and iodine.

These elements are

Hydrogen (H2)

Oxygen (2)

Fluorine (2)

Bromide (2)

Iodine (2)

Nitrogen (2)

Chlorine (2)


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These are written as the element, followed by Gas, keep in mind the exceptions of bromine iodine

Try these:

H2____________________

Br2___________________

Nitrogen gas____________

Fluorine gas____________

Molecules with common names

Water H2O

Ammonia NH3

Hydrogen peroxide H3O2

Methane CH4

Ozone O3

Try these

Name Symbol Symbol Name

Carbon Dioxide CF4Silicon Dioxide NH3

Water Pbr3

Carbon Disulfide O3

Sulfur trioxide F2 (gas)

Ammonia CS2

Carbon Tetrachloride N2O4

Hydrogen peroxide H2O2

Methane CO

Ozone (Trioxide) SiC

Diphosphorus trioxide P2O5

Nitrogen trioxide CH4Nitrogen monoxide SO3

Chlorine dioxide H2O

Dinitrogen oxide SiO2

Carbon monoxide PCl5

Arsenic tribromide I2 (gas)

Phosphorus pentabromide NO2

Dinitrogen tetroxide SF4

Silicon carbide H2 (gas)

Chemical equationsIntroduction

Chemical reactions can be written as equations . The format in which these are displayed is:

Reactant(I) + Reactant (II)Product(I) + Product (II)


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Example

In the case of H2OH2 + O2 Not balanced

Add a co-efficient of 2 to H2O and H2

This becomes 2H2O2H2 + O2

Strategies for balancing equations

Start from left to right

Do one element at a time.

Dont forget to change only the co-efficient; do not change subscripts

Acids and basesAci ds

Acids are compounds that increase the amount of hydrogen ions in water

Ex: HCL: The hydrogen atom dissolves from the chlorine atom to form two ions in water.

HCL(aq) --> H + Cl

Polyatomics in acids

Some polyatomics will also form acids in water.

Example

NO3 + H --> HNO3

Try these

Acetic acid: HCH3COO

Nitric acid: HNO3

Nitrous acid: HNO2

Chloric acid: HCLO3

Carbonic acid: H2CO3

Sulfuric acid: H2SO4

Sulfurous acid: H2SO3

Phosphoric acid: H3PO4

Characteristics of acids

Sour taste

Water soluble

Good at conducting electricity

Corrosive in high concentrations

Represented by 0-6 on a pH scale


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Making acidsAcids are made with non-metals

These non-metals can be combined with oxygen through combustion, and this will react with water to

form an acid

Example I

S+ O2 -->SO3

C + O2 --> CO2

Example II

SO3 + H2O --> H2SO4

CO2 + H2O --> H2CO3

Note: These equations can work both ways, go to types of reactions (Below) for more information.

The composition of bases

Bases increase the amount of hydroxide ions in water

Ex: NaOHNaOH (aq) --> Na + O

Metals can join with OH to form bases

Ex: Ca + OH --> Ca(OH)2

Try these

Potassium hydroxide________________________________________KOH

Aluminium hydroxide________________________________________Al(OH)2

Iron (II) Hydroxide __________________________________________Fe(OH)2

Copper (I) Hydroxide________________________________________CuOH

Characteristics of bases

Bitter taste

Water soluble

Slippery texture

Conducts electricity

Represented by numbers 8-14 on the pH scale

Making BasesBases are made with metals

Metals can be reacted with water (if reactive enough) to form bases

Ex: K + H2O --> H2O + KOHIf the metals do not react in water, they can be combined with oxygen (by combustion) to form a metal

oxide and then added to water to form a base.

Metal oxides are always solid

Try these


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Symbol Acid or Base NameKOH base potassium hydroxideH2SO4

acid

Sulfuric acid

H2CO3 ACID hydro carbonic acidNaOH base sodium hydroxideHCl acid hydrochloric acidNeutrality

Neither an acid or a base, and represented by 7 on a pH scale.

when they combine, hydrogen ions form the acid combine with the hydroxide ions to form the base,

making water. This reduces the number of H and OH in both solutions, making them more neutral.

Example

HCl +NaOH

H + Cl + Na + OH --> H2O +NaCl

Indicators

We can identify acids and bases using indicators. An indicator will change colour in the presence of

hydrogen ions or hydroxide ions.

List of indicators most commonly known

Indicator Color in acid Color in baselitmus red bluephenolphthalein colorless pinkBromothymol blue yellow blue

The pH scale

pH stands for power of hydrogen, meaning the concentration of hydrogen ions in a solution

The scale:

Acidic Neutral Basic

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14The pH scale is what we call a log scale, meaning logarithmic.Each step on the pH scale represents a 10x change in concentration of hydrogen ions


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Ex: pH 3 is 10x more acidic than pH 4pH 3 is 100x more acidic than pH 5

Types of reactions

Many chemical reactions (although not all of them) can be classified into one of four major categories, In

each case the reactions involve the rearrangement of atoms.

Synthesis

A synthesis reaction also called an addition or combinations reaction, is a reaction in which atoms and

molecules join together to produce larger molecules.

Equations for synthesis reactions are usually of the type:

A + B --> AB

Example

2H2 +O2 --> 2H2O

Decomposition

Decomposition are just the opposite of synthesis reaction. in the case one compound decomposes, or

breaks down in two.

Equations for decomposition reactions are usually of this type:

AB --> A + B

Example

2H2O --> 2H2 +O2

Single displacement

Displacement reactions involve a change of partners. In these reactions, one atom or group of atoms is

replaced by another atom or group of atoms.

Equations for displacement are usually of the type:

A + BC --> AC + B

Example

Cu + 2AgNO3 --> Cu (NO3)2 + 2AG

Double displacement

Double displacement reactions involve a joint exchange of partners. In other words, both of the

compounds changed their partners to produce two new compounds.

Equations for double displacement:

AB + CD --> AD + CB

Example

2KI + Pb(NO3)2 --> PbI2 + 2KNO3


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Optics Study DocumentThe ray model of lightLight generally travels in straight lines, unless it encounters different mediums or optical densities.

This can be shown through optical ray diagrams:

The orange circle emits light; this light is represented by the lines ending in arrows. The arrows indicate

the direction of travel of the rays. We can use ray diagrams like these to explain and demonstrate

different phenomena we see with light, such as in mirror problems.

How do we see things? ExplanationWe see things because they reflectlight from other light sources into our eyes.

Most objects give off light in all directions (scatter) because they dont have a very smooth surface.

Mirrors on the other hand have a very smooth surface, so they generally give off light in one direction.

Light that scatters off of uneven surfaces is divergent light

Even surface Uneven surface (Divergent light)

Our eyes tell us where light diverges from, for example

Sun


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We can use ray diagrams to figure out if we can see something in a mirror.

Example

Raymond has a neck injury that prevents him from looking down (how unfortunate). He wants to look at

his shoes and all he has is a mirror mounted on the wall at about eye level. He is standing at a set

distance from the mirror.

Raymond cannot see his feet.

Light wavesA wave of light is a disturbance that transfers energy from one point to another, like the ripples in a

pond after you throw a stone in it.

Wavelength: The distance from one place in a wave to the same point in the next wave. Represented by

lambda ()

Frequency: The rate of wave repetition. Measured in Hz (Hertz, cycles per second) represented by F

Speed: How quickly the wave travels. (velocity) Represented by S

Frequencies and wavelength are related

As frequencies increase, wavelengths decrease

As frequencies decrease, wavelengths increase

Frequency and wavelength have an inverserelationship

The mathematical relationship between speed (v), frequency (f) and wavelength ()is

Speed= frequency X wavelength

)


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ExampleIf the wavelength is .10m and the frequency is 5 Hz, what is the speed

Given =.1 and f=5Hz

Required: v=?

)

Substitute known values

Statement

The speed of the wave is .50 metres per second

Practice

1. Two children are skipping rope in a park, they produce waves by moving the rope up and down.

If the waves are .3 metres in length and they produce the waves at .5 m/s, what is the frequency

of the waves?

2. Radio waves travel at the speed of light (299,792,458 m/s), and can be 30 metres long, what is

the frequency of these waves

3. Some students are dropping weights in a pool, making ripples, the ripples are moving at about 5m/s and at a frequency of 420 Hz, how long are the ripples

4. A boat bobs up and down on a lake at a frequency of 20 Hz (cycles per minute), if the

wavelengths are .5 metres long, what is the speed of the waves


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Considering that all lines start from one point, where they (all three lines) converge, meaning come

together, is where that point will be reflected to, on the other side of the parallel axis

The image must now be described, the way to describe this is with SALT, salt is

Size: Can be larger or smaller

Attitude: upright or inverted

Location: Beyond, between or in front of the focus

Type: Real or virtual

Explanation of SALT

Sizeis the size in comparison to the original shape

Attitudeis whether it is the same way the shape is pointing or if it is flipped around

Locationis where the reflected image is in comparison to the focus

Typeis where the arrow is drawn in with regards to the mirror, if it is in front; it is real, if behind then

virtual

App li catio n of sa lt to th e above diagram

Size: Larger

Attitude: Inverted

Location: Beyond the focus

Type: Real


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Diverging mirrorsAlso known as a convex mirror, the reflecting surface curves outward

The line rules from converging mirrors apply to diverging mirrors, but in this instance, the focus and the

centre of curvature are on the opposite of mirror

1. Lines that are parallel to the normal will reflect at the same angle as if they go through the focus

2. Lines that align to go through the focus will come back out parallel to the normal

3. A ray to the vertex will have the same angle of incidence as that of reflection

4. A line going through the centre of curvature will come straight back

Dont forget SALT

Size: Smaller

Altitude: upright

Location: in front of

Type: Virtual

Note that if the object is on the focus, no image is formed, and if it is in front of the focus, the image

will be virtual.

Snells Law


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Snells law is a formula that uses values for the index of refraction to calculate the new angle that light

ray will take after entering a different medium.

In Snells law, the indexes of refraction of the two media areand , the angles of incidence and

refraction are and

The Formula for Snells law is

When encountering, use the G.R.A.S.S method and the formula, re-arrange formula if need be.

Example

Use the G.R.A.S.S method to solve for the angle of refraction

Given

Index of refraction of air

Index of refraction of still water

Angle of incidence

Required

Angle of refraction

Analysis and solution

Statement

The angle of refraction is approximately


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RefractionLenses like those in glasses and microscopes use refraction to direct light and focus it. When light moves

through a medium that is more or less optically dense, the light will bend

Refraction properties are also used in fiber optics to transmit information. Fiber optics transmits

information at the speed of light. Fiber optics also allow the use of a higher bandwidth.

Refraction is the bending of light rays as they pass from one medium into another

Refraction occurs when light slows down or speeds up because it passes from one medium to another

medium with different optical density

Optical density, also known as the index of refraction is a measure of how much the speed of light is

slowed down in that medium. The higher the optical density, the slower light travels. This is why deeper

bodies of water seem shallower to the naked eye and straws and spoons seem to break when they enter

a glass of translucent liquid.

Light travelling from a less optically dense medium will move towards the normal

Light travelling from a more optically dense medium will move away from the normal

Finding the index of refractionThe formula for finding the index of refraction is

n is the refractive index

c is the speed of light in a vacuum

v is the speed of light in the medium the refractive index is being calculated for

Example

The speed of light in a sample of glass is

Calculate the reflective index of the glass using the speed of light in a vacuum using

GRASS

Given

The speed of light in the sample

The speed of light in a vacuum

Required


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Analysis and solution

Manipulate the equation to solve for other variables

Climate ChangeThe Greenhouse effectThe greenhouse effect happens when sunlight passes through the atmosphere. Some of the solar

radiation is absorbed, while the rest reflects back as infrared radiation

Some of the infrared radiation is contained within the atmosphere, because of greenhouse gasses.

Gasses like carbon monoxide, methane and ozone trap some of the radiation. This heats the

atmosphere.

Although this is good, because it ensures that our planet stays at a good temperature, too many

greenhouse gasses will cause the temperature to rise


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The carbon cycle

Carbon Gas Emissions

Carbon offsets

Individuals or corporation can purchase carbon offsets to reduce their carbon footprints. These offsets

compensate for their greenhouse gas emissions by contributing money or resources to improve a

carbon sink.

The money provided has various uses; the main uses are development of renewable energy and re-

forestation.

Emissions trading

Governments can legislate the reduction of greenhouse gas emissions. A government may decide on the

annual amount of carbon Dioxide that each company can emit. If a company reduces its emissions to

under the government rate, they can trade the surplus allowance of carbon to other companies who

have exceeded their maximums.

CO2

Air and Water

Photosynthesis

Organiccompounds of

autotrophs

Consumed byheterotrophs

Organiccompounds ofheterotrophs

CellularRespiration

Cellular

respiration and

Burning

Decay of

organics


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Carbon Tax

A fee that is payable from an individual or company for creating greenhouse gasses. It is considered a

tax for polluting our atmosphere. The government collects these taxes and uses them to neutralize the

amount of harm being done to the atmosphere.

The effects of climate change in the atmosphere

Heat waves

A hot, humid and often smoggy air mass in an area is a heat wave. Heat waves are becoming more

frequent, wide spread and severe than in the past. As air becomes warmer, soil, lakes and rivers will

become warmer, potentially causing a shift in climate zone borders.

Drought

With no seasonal precipitation, water sources recede, soil and crops dry up, and animals die, leaving thepopulation with inadequate food and water supply.

Floods

When the air temperature warms up rapidly in spring, the snow can melt too quickly for the rivers and

streams to handle the run off. These seasonal floods can damage property, crop land and habitats.

Floods are becoming much more frequent and severe.

The effects of climate change on wildlife

The territory of some animals and plants are shifting, this threatens many organisms.

There has been a decline in fish stocks, such as pacific salmon due to increasing ocean temperatures

Because of artic sea ice melting, polar bear populations have been decreasing, and the bears have been

found more south than ever before

Other organisms however benefit from increased temperatures

Free living jellyfish populations have increased in coastal areas of oceans

Many organisms gain a larger habitat because of the warming.

Evidence of climate changeIce cores: Ice contains bubbles of air, and samples of water that give clues about weather patterns in

certain years, seasons and periods


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Tree rings: Because each tree ring is formed each year, the size of these rings can give clues to weather

patterns in a certain year. A larger ring means that there were better growing conditions at the time

Ice Cover: Measuring the amount of ice, and its receding/expanding gives climatologists key information

about climate change

Climoraphs: Show average monthly and yearly precipitation and temperatures. They demonstrate how

the climate patterns are changing

Extreme weather events: Climate change causes more extreme and frequent weather patterns,

tornadoes, hurricanes and intense storms are a product of global warming.

grade 10 science exam review-2

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